I first reported this in the Windows > Windows 7 Forums > System repair and recovery forum and we've reached a point where the moderator is recommending I post here. This error is now apparently affecting my ability to install important updates, not just the applications mentioned in my original post here - http://social.answers.microsoft.com/Forums/en-US/w7repair/thread/2f0b8f01-81c8-4bc3-8a82-5a208c43c1b2?prof=requiredText from original post - This error is occurring while attempting to install iTunes 9.0.2. However, I don't think that iTunes is to blame. Earlier, I installed Pinnacle Studio 11.0 but that application would crash. Updating it to 11.1 didn't solve anything. However, something changed and I was unable to uninstall Studio due to permissions even though I was logged in as admin. I ended up rolling the system back to just before the Studio install and thought things were good. But apparently not. I'm not sure if this failed install corrupted the Windows Installer Service or not, but it's obvious that it now needs fixing.I've searched for help on this and most of what I find is for XP. And I'm not ready to follow that advise yet.How do I fix the Windows Installer Service in Windows 7? By the way, I've checked and the service is currently running.At this point I'm trying to decide whether I re-install Windows 7 from scratch. This is not a good option. Please tell me that there is a much easier way to resolve this issue.

What is logged in the Event Viewer on the error?

I'm getting the following, System - Provider [ Name] MsiInstaller - EventID 11719 [ Qualifiers] 0 Level 2 Task 0 Keywords 0x80000000000000 - TimeCreated [ SystemTime] 2009-11-11T04:13:56.000000000Z EventRecordID 2815 Channel Application Computer Maui - Security [ UserID] S-1-5-21-1686193275-4023466625-1022617436-1001 - EventData Product: Windows Live Family Safety -- Error 1719. The Windows Installer Service could not be accessed. This can occur if the Windows Installer is not correctly installed. Contact your support personnel for assistance. (NULL) (NULL) (NULL) (NULL) (NULL) 7B46373531334531392D363232342D343835452D393838442D3942463435424536344235337D Binary data: In Words 0000: 3537467B 31453331 32362D39 342D3432 0008: 2D453538 44383839 4642392D 45423534 0010: 35423436 7D33 In Bytes 0000: 7B 46 37 35 31 33 45 31 {F7513E10008: 39 2D 36 32 32 34 2D 34 9-6224-40010: 38 35 45 2D 39 38 38 44 85E-988D0018: 2D 39 42 46 34 35 42 45 -9BF45BE0020: 36 34 42 35 33 7D 64B53}

Can you export the following registry key:HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\msiserverThen upload the resulting .reg file to Windows Live SkyDrive or similer site and provide the link?The problem may be at that registry key.Also, I did not see in your other thread that you actually re-registered the Windows Installer ( msiexec ). Did you re-register the Windows Installer?

http://support.microsoft.com/default.aspx/kb/315346

I've uploaded the exported registry key to SkyDrive as you suggested. It can be found at http://cid-3fadc8e2cf9396da.skydrive.live.com/self.aspx/.Public/msiserver.reg.And yes, I did re-register the Windowsss Installer.

Your uploaded reg. file looks to be incomplete missing required data for the service to operate.

Is it possible that this might be fixed by adding the missing registry data? I read the KB 315346 and I noticed that it has you restart the Windows Installer in SafeMode. When I did the re-start, it wasn't in SafeMode. Would this make a difference?

Something must have affected that registry key and it should be replaced with a good working copy.I would suggest to create a System Restore point and then delete the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\msiserver registry key.Then import that key from a working Windows 7 installation or use the following to create a .reg file: Windows Registry Editor Version 5.00 [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\msiserver] "DisplayName"="@%SystemRoot%\\system32\\msimsg.dll,-27" "ImagePath"=hex(2):25,00,73,00,79,00,73,00,74,00,65,00,6d,00,72,00,6f,00,6f,00,\ 74,00,25,00,5c,00,73,00,79,00,73,00,74,00,65,00,6d,00,33,00,32,00,5c,00,6d,\ 00,73,00,69,00,65,00,78,00,65,00,63,00,2e,00,65,00,78,00,65,00,20,00,2f,00,\ 56,00,00,00 "Description"="@%SystemRoot%\\system32\\msimsg.dll,-32" "ObjectName"="LocalSystem" "ErrorControl"=dword:00000001 "Start"=dword:00000003 "Type"=dword:00000010 "DependOnService"=hex(7):72,00,70,00,63,00,73,00,73,00,00,00,00,00 "ServiceSidType"=dword:00000001 "RequiredPrivileges"=hex(7):53,00,65,00,54,00,63,00,62,00,50,00,72,00,69,00,76,\ 00,69,00,6c,00,65,00,67,00,65,00,00,00,53,00,65,00,43,00,72,00,65,00,61,00,\ 74,00,65,00,50,00,61,00,67,00,65,00,66,00,69,00,6c,00,65,00,50,00,72,00,69,\ 00,76,00,69,00,6c,00,65,00,67,00,65,00,00,00,53,00,65,00,4c,00,6f,00,63,00,\ 6b,00,4d,00,65,00,6d,00,6f,00,72,00,79,00,50,00,72,00,69,00,76,00,69,00,6c,\ 00,65,00,67,00,65,00,00,00,53,00,65,00,49,00,6e,00,63,00,72,00,65,00,61,00,\ 73,00,65,00,42,00,61,00,73,00,65,00,50,00,72,00,69,00,6f,00,72,00,69,00,74,\ 00,79,00,50,00,72,00,69,00,76,00,69,00,6c,00,65,00,67,00,65,00,00,00,53,00,\ 65,00,43,00,72,00,65,00,61,00,74,00,65,00,50,00,65,00,72,00,6d,00,61,00,6e,\ 00,65,00,6e,00,74,00,50,00,72,00,69,00,76,00,69,00,6c,00,65,00,67,00,65,00,\ 00,00,53,00,65,00,41,00,75,00,64,00,69,00,74,00,50,00,72,00,69,00,76,00,69,\ 00,6c,00,65,00,67,00,65,00,00,00,53,00,65,00,53,00,65,00,63,00,75,00,72,00,\ 69,00,74,00,79,00,50,00,72,00,69,00,76,00,69,00,6c,00,65,00,67,00,65,00,00,\ 00,53,00,65,00,43,00,68,00,61,00,6e,00,67,00,65,00,4e,00,6f,00,74,00,69,00,\ 66,00,79,00,50,00,72,00,69,00,76,00,69,00,6c,00,65,00,67,00,65,00,00,00,53,\ 00,65,00,50,00,72,00,6f,00,66,00,69,00,6c,00,65,00,53,00,69,00,6e,00,67,00,\ 6c,00,65,00,50,00,72,00,6f,00,63,00,65,00,73,00,73,00,50,00,72,00,69,00,76,\ 00,69,00,6c,00,65,00,67,00,65,00,00,00,53,00,65,00,49,00,6d,00,70,00,65,00,\ 72,00,73,00,6f,00,6e,00,61,00,74,00,65,00,50,00,72,00,69,00,76,00,69,00,6c,\ 00,65,00,67,00,65,00,00,00,53,00,65,00,43,00,72,00,65,00,61,00,74,00,65,00,\ 47,00,6c,00,6f,00,62,00,61,00,6c,00,50,00,72,00,69,00,76,00,69,00,6c,00,65,\ 00,67,00,65,00,00,00,53,00,65,00,41,00,73,00,73,00,69,00,67,00,6e,00,50,00,\ 72,00,69,00,6d,00,61,00,72,00,79,00,54,00,6f,00,6b,00,65,00,6e,00,50,00,72,\ 00,69,00,76,00,69,00,6c,00,65,00,67,00,65,00,00,00,53,00,65,00,52,00,65,00,\ 73,00,74,00,6f,00,72,00,65,00,50,00,72,00,69,00,76,00,69,00,6c,00,65,00,67,\ 00,65,00,00,00,53,00,65,00,49,00,6e,00,63,00,72,00,65,00,61,00,73,00,65,00,\ 51,00,75,00,6f,00,74,00,61,00,50,00,72,00,69,00,76,00,69,00,6c,00,65,00,67,\ 00,65,00,00,00,53,00,65,00,53,00,68,00,75,00,74,00,64,00,6f,00,77,00,6e,00,\ 50,00,72,00,69,00,76,00,69,00,6c,00,65,00,67,00,65,00,00,00,53,00,65,00,54,\ 00,61,00,6b,00,65,00,4f,00,77,00,6e,00,65,00,72,00,73,00,68,00,69,00,70,00,\ 50,00,72,00,69,00,76,00,69,00,6c,00,65,00,67,00,65,00,00,00,53,00,65,00,4c,\ 00,6f,00,61,00,64,00,44,00,72,00,69,00,76,00,65,00,72,00,50,00,72,00,69,00,\ 76,00,69,00,6c,00,65,00,67,00,65,00,00,00,00,00 "FailureActions"=hex:84,03,00,00,00,00,00,00,00,00,00,00,03,00,00,00,14,00,00,\ 00,01,00,00,00,c0,d4,01,00,01,00,00,00,e0,93,04,00,00,00,00,00,00,00,00,00 Restart the computer and see if the problem resolves.

Before you enter this .reg key verify that it is for a 64 bit system. If you are running windows 7 64 you will need a 64 bit registry entry.

This is for a Windows 7 64 bit system. So is the above key for a 32 or 64 bit system?

That is the exported key from a working 64-bit Windows 7 installation.But, I believe, the keyis the same on both 32-bit and 64-bit.

This is for a Windows 7 64 bit system. So is the above key for a 32 or 64 bit system? auggy?

Note howyours has "WOW64"=dword:00000001soauggy'smust befrom a 32 bit.Windows Registry Editor Version 5.00 [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\MSIServer]"Type"=dword:00000120"Start"=dword:00000003"ErrorControl"=dword:00000001"ImagePath"=hex(2):43,00,3a,00,5c,00,57,00,69,00,6e,00,64,00,6f,00,77,00,73,00,\ 5c,00,73,00,79,00,73,00,74,00,65,00,6d,00,33,00,32,00,5c,00,6d,00,73,00,69,\ 00,65,00,78,00,65,00,63,00,2e,00,65,00,78,00,65,00,20,00,2f,00,56,00,00,00"DisplayName"="Windows installer""WOW64"=dword:00000001ObjectName"="LocalSystem"

Note howyours has "WOW64"=dword:00000001soauggy'smust befrom a 32 bit. I don't know how that "WOW64"=dword:00000001got in there but it does notexist by default on a 64-bit installation.Again, something must have corrupted that registry key.

Importing the reg key above appears to have resolved this issue. Thank you, thank you, thank you.Dave.

You're welcome. Glad that worked.

I'm not sure if this is related or not. But I'm trying to apply some additional updates, via Windows Update, and I'm getting a Windows Installer dialog that is telling me the following, "The feature you are trying to use is on a CD-ROM or other removable disk that is not available." "Insert the 'Microsoft Office Live Add-in 1.4' disk and click OK."I do have MS Office Live 1.4 installed. But I don't have the disk it's asking for. Is is possible that there is further damage to my system that still needs to be fixed?Dave.