Hello!

I'm having an issue with my Windows 8 Enterprise install on my home PC. There's quite a bit to tell to get you up to speed unfortunately:

A few days ago I installed drivers and software for a Logitech webcam (250 model) that I've had for a while. Upon rebooting I received a stop error code 0xc000021a. The PC rebooted and tried an automatic repair of the problem which failed. The error code associated with this failure in the SRT log was 0x490. Attempting a boot into safe mode yielded the same error. Additionally, "Last known good configuration" isn't on by default in Windows 8, so that's no help...

Following these failures, I tried doing a system restore from the recovery environment on the Windows 8 Enterprise install disk I have. This informed me that I didn't have enough free space on the drive to do the restore (which I had forgotten was so low). To remedy this, I booted into one of the two Windows 7 installations I also have on the PC and removed a few large files from my user directory and emptied the recycle bin, freeing up a few GB.

Booting back into the RE via the Win 8 install disk, it then claimed I had no system restore points for that Windows installation at all. Confused, I tried booting back into Windows 8 as I would usually. It was then that I discovered the list of operating systems displayed by Win 8 to start was completely blank and didn't even include the Windows 8 installation.

Unsure sure how the BCD would get wiped in a situation like this, I booted back into the Win 8 disk RE and discovered that the RE could read the BCD just fine and listed all three operating systems (one Win 8 and two Win 7) just fine. Removing and rebuilding the BCD (and fixing the MBR, even though it wasn't broken) had no effect. Quickly running out of clever ideas, I tried starting the automatic repair again which surprisingly appeared to successfully complete. Windows 8 then booted normally.

Great! Except it was having serious issues... starting the task manager for example would show a warning about a DLL file not being suitable for the system or corrupt. All networking seemed to be braindead (I also saw one of these DLL errors for dhcpcsvc.dll). I poked around for a while, running some system tools, uninstalling the Logitech software, and making a new system restore point. CHKDSK and BOOTREC did their thing without anything of note, but SFC did find some corrupt files that it couldn't replace. I read that a recent windows update may be causing some false positives there, however. Since I can't post links until I'm verified apparently, here's some samples of relevant lines from the CBS.log file that SFC generated (the full text is here: http://pastebin.com/raw.php?i=eH6xZVY6 ):

• [SR] Cannot repair member file [l:16{8}]"acpi.inf" of acpi.inf, Version = 6.2.9200.16420, pA = PROCESSOR_ARCHITECTURE_AMD64 (9), Culture neutral, VersionScope = 1 nonSxS, PublicKeyToken = {l:8 b:31bf3856ad364e35}, Type = [l:24{12}]"driverUpdate", TypeName neutral, PublicKey neutral in the store, hash mismatch
• [SR] Cannot verify component files for c970964bc4fb3a3297146d029a54c96e, Version = 4.0.9200.16575, pA = PROCESSOR_ARCHITECTURE_AMD64 (9), Culture neutral, VersionScope = 1 nonSxS, PublicKeyToken = {l:8 b:b03f5f7f11d50a3a}, Type neutral, TypeName neutral, PublicKey neutral, manifest is damaged (TRUE)
• [SR] Cannot repair member file [l:24{12}]"dhcpcsvc.dll" of Microsoft-Windows-DHCP-Client-Dll-MinWin, Version = 6.2.9200.16433, pA = PROCESSOR_ARCHITECTURE_AMD64 (9), Culture neutral, VersionScope = 1 nonSxS, PublicKeyToken = {l:8 b:31bf3856ad364e35}, Type neutral, TypeName neutral, PublicKey neutral in the store, hash mismatch
• [SR] Cannot repair member file [l:22{11}]"wdscore.dll" of Microsoft-Windows-PantherEngine, Version = 6.2.9200.16384, pA = PROCESSOR_ARCHITECTURE_AMD64 (9), Culture neutral, VersionScope = 1 nonSxS, PublicKeyToken = {l:8 b:31bf3856ad364e35}, Type neutral, TypeName neutral, PublicKey neutral in the store, hash mismatch
• [SR] Cannot repair member file [l:30{15}]"shdocvw.dll.mui" of Microsoft-Windows-shdocvw.Resources, Version = 6.2.9200.16550, pA = PROCESSOR_ARCHITECTURE_AMD64 (9), Culture = [l:10{5}]"en-US", VersionScope = 1 nonSxS, PublicKeyToken = {l:8 b:31bf3856ad364e35}, Type neutral, TypeName neutral, PublicKey neutral in the store, hash mismatch
• [SR] Cannot repair member file [l:26{13}]"djoin.exe.mui" of Microsoft-Windows-UnattendedJoin.Resources, Version = 6.2.9200.16384, pA = PROCESSOR_ARCHITECTURE_AMD64 (9), Culture = [l:10{5}]"en-US", VersionScope = 1 nonSxS, PublicKeyToken = {l:8 b:31bf3856ad364e35}, Type neutral, TypeName neutral, PublicKey neutral in the store, hash mismatch
• [SR] Cannot repair member file [l:50{25}]"DotNetTypes.format.ps1xml" of Microsoft.Windows.PowerShell.Common, Version = 6.2.9200.16384, pA = PROCESSOR_ARCHITECTURE_AMD64 (9), Culture neutral, VersionScope = 1 nonSxS, PublicKeyToken = {l:8 b:31bf3856ad364e35}, Type neutral, TypeName neutral, PublicKey neutral in the store, hash mismatch
• [SR] Cannot repair member file [l:24{12}]"vaultcli.dll" of Microsoft-Windows-Security-Vault, Version = 6.2.9200.16384, pA = PROCESSOR_ARCHITECTURE_IA32_ON_WIN64 (10), Culture neutral, VersionScope = 1 nonSxS, PublicKeyToken = {l:8 b:31bf3856ad364e35}, Type neutral, TypeName neutral, PublicKey neutral in the store, hash mismatch
• [SR] Cannot repair member file [l:30{15}]"shdocvw.dll.mui" of Microsoft-Windows-shdocvw.Resources, Version = 6.2.9200.16550, pA = PROCESSOR_ARCHITECTURE_INTEL (0), Culture = [l:10{5}]"en-US", VersionScope = 1 nonSxS, PublicKeyToken = {l:8 b:31bf3856ad364e35}, Type neutral, TypeName neutral, PublicKey neutral in the store, hash mismatch
• [SR] Cannot repair member file [l:22{11}]"wdscore.dll" of Microsoft-Windows-PantherEngine, Version = 6.2.9200.16384, pA = PROCESSOR_ARCHITECTURE_AMD64 (9), Culture neutral, VersionScope = 1 nonSxS, PublicKeyToken = {l:8 b:31bf3856ad364e35}, Type neutral, TypeName neutral, PublicKey neutral in the store, hash mismatch
• [SR] Could not reproject corrupted file [ml:520{260},l:46{23}]"\??\C:\Windows\System32"\[l:22{11}]"wdscore.dll"; source file in store is also corrupted

Being again, out of ideas, I tried a reboot, and as you may have guessed, everything was as it was before. The operating system list was blank as before and only accessible via the recovery environment. Trying to boot into Windows 8 from there yields another unsuccessful automatic repair. It should be noted at this point that I haven't actually seen the original problem 0xc000021a stop code since accessing the recovery environment on the Windows 8 install disk originally.

At this point I'm completely out of ideas. Clearly some system files are in bad shape, but not so bad that booting is impossible. If I don't have a good system restore point to roll back to, and SFC can't fix what it found for some reason (assuming its not a false positive), what other recourse do I have, short of a system refresh?

Any help anyone can give or any part of this you might be able to shed light on would be greatly appreciated!

Additional things I've tried since posting originally: 

• Cloned the Windows 8 install partition to a separate drive and added that to the BCD - same issues as before but now it is booting reliably, but with the DLL errors mentioned before.
• Took a closer look at the CBS log and saw the system file store also has corruption issues - attempted using DISM to repair.
• For some reason, running the oft-mentioned DISM /Online /Cleanup-Image /ScanHealth command returns error 87: the cleanup-image option is unknown. I've tried every combination I can think of, as well as specified the full path to the executable, all to no avail. Error 87 is always returned for the Cleanup-Image option.

This question is also posted here: http://answers.microsoft.com/en-us/windows/forum/windows_8-system/windows-8-wont-boot-possible-dll-corruption-wont/31b3dfd0-8604-4206-8d25-cf32f47a4de0

Hi,

Did you try to rebuild BCD:

http://pcsupport.about.com/od/fixtheproblem/ht/rebuild-bcd-store-windows.htm

If the issue persists, try to insert win 8  installation disc and perform system refresh for test.