Windows 7 SP 1 appears to have failed on two of my 64-bit workstations with Fatal Error C0000034. Fortunately I found a very detailed report over at Microsoft Forums that matched my scenario. The solution is a manual system restore. In short it tells us to revert to default files in Windows\System32\config.
You may recognize this as a Vista manual system restore:
I was finally able boot Windows 7, but now the Windows Installer 5.0 is broken. "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." This is true with any MSI file including Windows Updates.
I looked for a redistributable of Installer 5.0 with no luck.
In Windows Update history Win 7 SP 1 (KB976932) appears as installed, but when I check for updates it's still on-deck. This is a problem. I tried to reinstall it but the job hangs.
I downloaded the SP 1 iso file from the Microsoft Download Center; the package knows instantly that Windows Installer is broken.
I tried some Windows XP fixes. Does these still apply to Windows 7?
ren msihnd.dll msihnd.old
I have no permissions to access msi.dll. I didn't have time to play with ownership before I got called to look at something else.
I hope that Microsoft is playing catch-up on this one. I'd really appreciate some advice. Thanks.