Hello, I was reviewing my logs and noticed that, after installing KB941314 on a fresh install of Vista Ultimate SP1 (x86), the .NET assembly optimization tool ran into an error (attached below). There doesn't seem to be much information on it from what I can tell, so I thought I would see if anyone else has noticed the same thing in their ngen*.log logs. Note that the same error resurfaces every time the GAC is updated using ngen update. I haven't had any problems yet actually running the tools, but the error is somewhat concerning. It would indicate that the assembly image was invalid. However SFC does not report anything awry with the actualdll in WinSxS. Here is the output of my ngen.log: Code Snippet 03/27/2008 09:39:50 [3528]: Failed to load dependency Microsoft.GroupPolicy.Targeting.Interop of assembly Microsoft.GroupPolicy.Targeting, Version=2.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35 because of the following error : The operating system cannot run . (Exception from HRESULT: 0x800700B6)03/27/2008 09:39:50 [3528]: Compiling assembly Microsoft.GroupPolicy.Targeting, Version=2.0.0.0, Culture=Neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=msil ...03/27/2008 09:39:50 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0x1000019 - Microsoft.GroupPolicy.Targeting.TaskDialogResult.03/27/2008 09:39:50 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0x100001e - Microsoft.GroupPolicy.Targeting.TaskDialogIcon.03/27/2008 09:39:50 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0x100001f - Microsoft.GroupPolicy.Targeting.TaskDialogButtons.03/27/2008 09:39:50 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0x1000020 - Microsoft.GroupPolicy.Targeting.TaskDialogButton.03/27/2008 09:39:50 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0x1000021 - Microsoft.GroupPolicy.Targeting.TaskDialogDefaultButton.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0x100004a - Microsoft.GroupPolicy.Targeting.MsiBrowserMode.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0x1000051 - Microsoft.GroupPolicy.Targeting.RegistryValueBase.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0x100006e - Microsoft.GroupPolicy.Targeting.VariableBrowserDialog.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0x1000070 - Microsoft.GroupPolicy.Targeting.MmcHelper.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0x1000097 - Microsoft.GroupPolicy.Targeting.TaskDialog.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0x10000d4 - Microsoft.GroupPolicy.Targeting.ActiveDirectoryBrowserDialog.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0x10000d5 - Microsoft.GroupPolicy.Targeting.ActiveDirectoryBrowserBehaviors.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0x10000d6 - Microsoft.GroupPolicy.Targeting.ActiveDirectoryBrowserModes.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0x10000e7 - Microsoft.GroupPolicy.Targeting.Locale.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0x10000e9 - Microsoft.GroupPolicy.Targeting.MsiBrowserDialog.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0x10000f1 - Microsoft.GroupPolicy.Targeting.RegistryBrowserDialog.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0x10000f2 - Microsoft.GroupPolicy.Targeting.RegistryBrowserSelection.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0x10000f4 - Microsoft.GroupPolicy.Targeting.ActiveDirectoryBrowserGroupInfo.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0x10000f9 - Microsoft.GroupPolicy.Targeting.ActiveDirectoryBrowserUserInfo.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0xa000021 - Microsoft.GroupPolicy.Targeting.VariableBrowserDialog..ctor.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0xa000022 - Microsoft.GroupPolicy.Targeting.VariableBrowserDialog.set_ShowResolveVariableButton.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0xa000023 - Microsoft.GroupPolicy.Targeting.VariableBrowserDialog.set_WantVariableName.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0xa000025 - Microsoft.GroupPolicy.Targeting.VariableBrowserDialog.get_VariableName.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0xa000027 - Microsoft.GroupPolicy.Targeting.MmcHelper.ShowHelpTopic.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0xa00007a - Microsoft.GroupPolicy.Targeting.TaskDialogButton..ctor.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0xa00007c - Microsoft.GroupPolicy.Targeting.TaskDialog..ctor.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0xa00007d - Microsoft.GroupPolicy.Targeting.TaskDialog.set_RightToLeftLayout.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0xa00007e - Microsoft.GroupPolicy.Targeting.TaskDialog.set_Title.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0xa00007f - Microsoft.GroupPolicy.Targeting.TaskDialog.set_MainInstruction.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0xa000080 - Microsoft.GroupPolicy.Targeting.TaskDialog.set_Content.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0xa000081 - Microsoft.GroupPolicy.Targeting.TaskDialog.set_MainIcon.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0xa000082 - Microsoft.GroupPolicy.Targeting.TaskDialog.set_CommonButtons.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0xa000083 - Microsoft.GroupPolicy.Targeting.TaskDialog.set_DefaultButton.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0xa000084 - Microsoft.GroupPolicy.Targeting.TaskDialog.set_AllowDialogCancellation.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0xa000085 - Microsoft.GroupPolicy.Targeting.TaskDialog.get_CustomButtons.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0xa000087 - Microsoft.GroupPolicy.Targeting.TaskDialog.ShowDialog.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0xa000088 - Microsoft.GroupPolicy.Targeting.TaskDialog.set_UseCommandLinks.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0xa00018a - Microsoft.GroupPolicy.Targeting.ActiveDirectoryBrowserDialog..ctor.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0xa00018b - Microsoft.GroupPolicy.Targeting.ActiveDirectoryBrowserDialog.set_BrowserBehaviors.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0xa00018c - Microsoft.GroupPolicy.Targeting.ActiveDirectoryBrowserDialog.set_BrowserModes.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0xa00018e - Microsoft.GroupPolicy.Targeting.ActiveDirectoryBrowserDialog.get_Host.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0xa0001c6 - Microsoft.GroupPolicy.Targeting.ActiveDirectoryBrowserDialog.get_Domain.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0xa0001f2 - Microsoft.GroupPolicy.Targeting.Locale.MakeLanguageId.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0xa0001f3 - Microsoft.GroupPolicy.Targeting.Locale.MakeLcid.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0xa0001f5 - Microsoft.GroupPolicy.Targeting.Locale.GetLanguageIdFromLcid.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0xa0001f6 - Microsoft.GroupPolicy.Targeting.Locale.GetPrimaryLanguageId.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0xa0001f8 - Microsoft.GroupPolicy.Targeting.Locale.GetSublanguageId.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0xa000201 - Microsoft.GroupPolicy.Targeting.MsiBrowserDialog..ctor.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0xa000202 - Microsoft.GroupPolicy.Targeting.MsiBrowserDialog.get_MsiGuid.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0xa000223 - Microsoft.GroupPolicy.Targeting.ActiveDirectoryBrowserDialog.get_OrganizationalUnit.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0xa000238 - Microsoft.GroupPolicy.Targeting.RegistryBrowserDialog..ctor.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0xa000239 - Microsoft.GroupPolicy.Targeting.RegistryBrowserDialog.get_BrowserResult.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0xa00023a - Microsoft.GroupPolicy.Targeting.RegistryBrowserSelection.get_Hive.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0xa00023b - Microsoft.GroupPolicy.Targeting.RegistryBrowserSelection.get_Key.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0xa00023c - Microsoft.GroupPolicy.Targeting.RegistryBrowserSelection.get_IsDefaultValue.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0xa00023d - Microsoft.GroupPolicy.Targeting.RegistryBrowserSelection.get_ValueName.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0xa00023e - Microsoft.GroupPolicy.Targeting.RegistryBrowserSelection.get_ValueKind.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0xa00023f - Microsoft.GroupPolicy.Targeting.RegistryBrowserSelection.get_ValueBase.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0xa000240 - Microsoft.GroupPolicy.Targeting.RegistryBrowserSelection.get_ValueData.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0xa000241 - Microsoft.GroupPolicy.Targeting.RegistryBrowserSelection.get_ValueDataMultiString.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0xa000247 - Microsoft.GroupPolicy.Targeting.ActiveDirectoryBrowserDialog.get_Group.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0xa000248 - Microsoft.GroupPolicy.Targeting.ActiveDirectoryBrowserGroupInfo.get_SecurityIdentifier.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0xa00024c - Microsoft.GroupPolicy.Targeting.ActiveDirectoryBrowserGroupInfo.get_BuiltIn.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0xa00024d - Microsoft.GroupPolicy.Targeting.ActiveDirectoryBrowserGroupInfo.get_Name.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0xa00024f - Microsoft.GroupPolicy.Targeting.ActiveDirectoryBrowserDialog.get_SiteName.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0xa000263 - Microsoft.GroupPolicy.Targeting.ActiveDirectoryBrowserDialog.get_User.03/27/2008 09:39:51 [3528]: Warning: System.BadImageFormatException: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while resolving 0xa000264 - Microsoft.GroupPolicy.Targeting.ActiveDirectoryBrowserUserInfo.get_SecurityIdentifier.03/27/2008 09:39:52 [3528]: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while compiling method Common.ShowVariableBrowser03/27/2008 09:39:52 [3528]: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while compiling method Common.ShowHelpTopic03/27/2008 09:39:52 [3528]: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while compiling method InputValidator.DisplayDwordOverflowMessage03/27/2008 09:39:52 [3528]: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while compiling method RtlAwareTaskDialog.ShowSimple03/27/2008 09:39:52 [3528]: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while compiling method RtlAwareTaskDialog.ShowSimple03/27/2008 09:39:52 [3528]: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while compiling method RtlAwareTaskDialog.Show03/27/2008 09:39:52 [3528]: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while compiling method NumericTextBoxHelper.HandleOverflowException03/27/2008 09:39:52 [3528]: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while compiling method FilterDesignerForm.ShowEmptyCollectionFoundPrompt03/27/2008 09:39:52 [3528]: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while compiling method ComputerNameFilterControl.computerNameBrowseButton_Click03/27/2008 09:39:52 [3528]: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while compiling method CpuSpeedFilterControl.cpuSpeedComboBox_Validating03/27/2008 09:39:52 [3528]: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while compiling method DomainFilterControl.browseForDomainButton_Click03/27/2008 09:39:52 [3528]: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while compiling method LanguageFilterControl.LoadFromXml03/27/2008 09:39:52 [3528]: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while compiling method LanguageFilterControl.SaveToXml03/27/2008 09:39:52 [3528]: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while compiling method MsiQueryFilterControl.msiBrowserButton_Click03/27/2008 09:39:52 [3528]: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while compiling method MsiQueryFilterControl.GetMsiBrowserMode03/27/2008 09:39:53 [3528]: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while compiling method OrganizationalUnitFilterControl.orgUnitBrowseButton_Click03/27/2008 09:39:53 [3528]: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while compiling method RamFilterControl.ramSizeComboBox_Validating03/27/2008 09:39:53 [3528]: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while compiling method RegistryMatchFilterControl.SetValueTypeFromBrowser03/27/2008 09:39:53 [3528]: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while compiling method RegistryMatchFilterControl.registryBrowserButton_Click03/27/2008 09:39:53 [3528]: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while compiling method SecurityGroupFilterControl.groupBrowseButton_Click03/27/2008 09:39:53 [3528]: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while compiling method SiteFilterControl.siteBrowseButton_Click03/27/2008 09:39:53 [3528]: The operating system cannot run . (Exception from HRESULT: 0x800700B6) while compiling method UserFilterControl.userBrowseButton_Click03/27/2008 09:39:55 [3528]: Microsoft.GroupPolicy.Targeting, Version=2.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e3503/27/2008 09:39:56 [3528]: Failed to find dependencies of image Microsoft.GroupPolicy.Targeting.Interop, Version=2.0.0.0, Culture=Neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=x86 because of the following error: The operating system cannot run . (Exception from HRESULT: 0x800700B6)03/27/2008 09:39:56 [3528]: Compiling assembly Microsoft.GroupPolicy.Targeting.Interop, Version=2.0.0.0, Culture=Neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=x86 ...03/27/2008 09:39:56 [3528]: Error compiling Microsoft.GroupPolicy.Targeting.Interop, Version=2.0.0.0, Culture=Neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=x86: The operating system cannot run . (Exception from HRESULT: 0x800700B6)