Not sure what happened. Exchange 2007 sp1 running on W2k8 RTM. Trying to remotely connect to OWA and all of a sudden now clients get this error message. RequestUrl: https://mail:443/owa/auth/error.aspx?aspxerrorpath=/owa/auth/logon.aspxUser host address: 192.168.1.111ExceptionException type: System.BadImageFormatExceptionException message: An attempt was made to load a program with an incorrect format. (Exception from HRESULT: 0x8007000B)Call stack System.Runtime.InteropServices.Marshal.ThrowExceptionForHRInternal(Int32 errorCode, IntPtr errorInfo) System.Management.ManagementScope.InitializeGuts(Object o) System.Management.ManagementScope.Initialize() System.Management.ManagementEventWatcher.Initialize() System.Management.ManagementEventWatcher.Start() Microsoft.Exchange.Clients.Owa.Core.OwaRegistryKeys.RegisterSMIMERegistryChangeEvent() Microsoft.Exchange.Clients.Owa.Core.OwaRegistryKeys.Initialize() Microsoft.Exchange.Clients.Owa.Core.Globals.InitializeApplication() Microsoft.Exchange.Clients.Owa.Core.Global.ExecuteApplicationStart(Object sender, EventArgs e) Haven't been able to find much so I tried to go through the steps of uninstalling Client Access but I get the same exception on which causes the uninstall to fail. Thus don't really want to try uninstalling IIS and reinstalling since can't run the uninstall or uninstall on exchange. Not sure what else to try here. Anyway to do better logging to get to the bottom of what's generating the exception? Or a way to forcibly remove Client Access Services and try reinstalling it? Thanks.

After troubleshooting this, looking at some exchange logs it seemed that anything it tried to do to the OS such as remove OWA virtual directory from IIS or when trying to uninstall Client Access service, I would get the exception. What I noticed is in all cases exchange was trying to do communicate with the OS. I then saw a couple of wmi calls on the stack in one instance so I opened up wmi. Trying to click properties on my machine, got the same 0x8007000B exception. Broke out to a command prompt trying to figure out how to reset wmi and stumbled across winmgmt /resetrepository Once that ran could go into wmi managment. http://207.46.199.254/en-us/library/aa394525(VS.85).aspx Trying going back to OWA voila, problem solved. So looks like corruption with WMI which it appears exchange relies on fairly heavily was the source of this problem. FUN, FUN!!!