Most programs not starting up

I downloaded a Windows Update the other day but then got an error that it didn't install correctly. Soon later my comp suddenly reboots by itself. Then when I log on I can't launch half of my programs. Things like notepad, command prompt, CCleaner, & task manager work. But things like Steam, Internet Explorer, FireFox, games, Notepad++, uninstallers, when you click them, you get the spinning circle for a couple seconds, then it goes back to the normal pointer like nothing ever happened, no processes show up in task manager.

So I tried doing a system restore, but that didn't work. Then I tried the sfc /scannow technique. Then it said there were some corrupted files that couldn't be repaired. I open the CBS log and here's the errors that it had.

Code:

POQ 194 ends.
2012-01-08 03:50:40, Info                  CSI    00000496 [SR] Verify complete
2012-01-08 03:50:41, Info                  CSI    00000497 [SR] Verifying 100 (0x0000000000000064) components
2012-01-08 03:50:41, Info                  CSI    00000498 [SR] Beginning Verify and Repair transaction
2012-01-08 03:50:41, Info                  CSI    00000499 Hashes for file member \SystemRoot\WinSxS\amd64_prnep00b.inf_31bf3856ad364e35_6.1.7600.16385_none_ad2d68ddc89d49d5\Amd64\EP0NCA9C.CMB do not match actual file [l:36{18}]"Amd64\EP0NCA9C.CMB" :
  Found: {l:32 b:47DEQpj8HBSa+/TImW+5JCeuQeRkm5NMpJWZG3hSuFU=} Expected: {l:32 b:eh4eSE7hvzA5UUlfdLhFhdxTyplhC5FCMT52spWNBEc=}
2012-01-08 03:50:41, Info                  CSI    0000049a [SR] Cannot repair member file [l:36{18}]"Amd64\EP0NCA9C.CMB" of prnep00b.inf, Version = 6.1.7600.16385, 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
2012-01-08 03:50:59, Info                  CSI    0000049b Hashes for file member \SystemRoot\WinSxS\amd64_prnep00b.inf_31bf3856ad364e35_6.1.7600.16385_none_ad2d68ddc89d49d5\Amd64\EP0NCA9C.CMB do not match actual file [l:36{18}]"Amd64\EP0NCA9C.CMB" :
  Found: {l:32 b:47DEQpj8HBSa+/TImW+5JCeuQeRkm5NMpJWZG3hSuFU=} Expected: {l:32 b:eh4eSE7hvzA5UUlfdLhFhdxTyplhC5FCMT52spWNBEc=}
2012-01-08 03:50:59, Info                  CSI    0000049c [SR] Cannot repair member file [l:36{18}]"Amd64\EP0NCA9C.CMB" of prnep00b.inf, Version = 6.1.7600.16385, 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
2012-01-08 03:50:59, Info                  CSI    0000049d [SR] This component was referenced by [l:186{93}]"Microsoft-Windows-Printer-Drivers-Package~31bf3856ad364e35~amd64~~6.1.7601.17514.INF_prnep00b"
2012-01-08 03:50:59, Info                  CSI    0000049e Repair results created:
POQ 195 starts:

POQ 248 ends.
2012-01-08 03:54:12, Info                  CSI    000005e8 [SR] Verify complete
2012-01-08 03:54:12, Info                  CSI    000005e9 [SR] Repairing 1 components
2012-01-08 03:54:12, Info                  CSI    000005ea [SR] Beginning Verify and Repair transaction
2012-01-08 03:54:12, Info                  CSI    000005eb Hashes for file member \SystemRoot\WinSxS\amd64_prnep00b.inf_31bf3856ad364e35_6.1.7600.16385_none_ad2d68ddc89d49d5\Amd64\EP0NCA9C.CMB do not match actual file [l:36{18}]"Amd64\EP0NCA9C.CMB" :
  Found: {l:32 b:47DEQpj8HBSa+/TImW+5JCeuQeRkm5NMpJWZG3hSuFU=} Expected: {l:32 b:eh4eSE7hvzA5UUlfdLhFhdxTyplhC5FCMT52spWNBEc=}
2012-01-08 03:54:12, Info                  CSI    000005ec [SR] Cannot repair member file [l:36{18}]"Amd64\EP0NCA9C.CMB" of prnep00b.inf, Version = 6.1.7600.16385, 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
2012-01-08 03:54:12, Info                  CSI    000005ed Hashes for file member \SystemRoot\WinSxS\amd64_prnep00b.inf_31bf3856ad364e35_6.1.7600.16385_none_ad2d68ddc89d49d5\Amd64\EP0NCA9C.CMB do not match actual file [l:36{18}]"Amd64\EP0NCA9C.CMB" :
  Found: {l:32 b:47DEQpj8HBSa+/TImW+5JCeuQeRkm5NMpJWZG3hSuFU=} Expected: {l:32 b:eh4eSE7hvzA5UUlfdLhFhdxTyplhC5FCMT52spWNBEc=}
2012-01-08 03:54:12, Info                  CSI    000005ee [SR] Cannot repair member file [l:36{18}]"Amd64\EP0NCA9C.CMB" of prnep00b.inf, Version = 6.1.7600.16385, 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
2012-01-08 03:54:12, Info                  CSI    000005ef [SR] This component was referenced by [l:186{93}]"Microsoft-Windows-Printer-Drivers-Package~31bf3856ad364e35~amd64~~6.1.7601.17514.INF_prnep00b"
2012-01-08 03:54:12, Info                  CSI    000005f0 Repair results created:
POQ 249 starts:

I go to the files in question, but I can't do anything with them. When I try changing the permissions on them, I get an "access is denied" even though I'm an administrator. So now what do I do?

I tried doing a repair install of Windows 7, but when the comp restarted I get an error message

winpeshl.exe - Application Error
The application was unable to start correctly (0xc0000142). Click OK to close the application.

Then it restarts and takes me to a new W7-type login screen. Except the profile picture is blank, and there's a username and password field. But no matter what I put in them, I get an error saying "The specified domain either does not exist or could not be contacted." and it takes me back.