Answer: Parts of the hard drive are corrupted. All of my user's code was checked in, so I'm just going to format the box.

One of my users has an HP DV5-1235dx laptop running Windows Vista Professional x64. Last night, our WSUS server pushed out a few updates including "Security Update for Windows Vista for x64-based Systems (KB960859)". When we try to boot the laptop today, a black screen with white text comes up displaying:

xxx/169894 (something)

Where xxx increments rapidly and something is some dll or registry key.

Eventually that stops and the screen displays

!! 0xc01a00d !! 35566/169894 (\Registry\Machine\COMPONENTS\DerivedDat...)

No other computers that received this update are displaying the same error.

So far I've tried running CHKDSK off of HBCD. It repaired a thing or two, but the computer still doesn't boot. I tried repairing the Windows install from the Vista CD, but I get a black screen with white text displaying something along the lines of:

0 No Emulation System Type 00
1 No Emulation System Type 00
Select one of the above

Booting in Last Known Good Configuration doesn't work. Booting in Safe Mode freezes at

Loading Windows Files
[snip]
Loaded: \windows\system32\drivers\crcdisk.sys
Please wait...

My next step is trying to boot Safe Mode with Command Prompt and try to run rstrui.exe. While I do that, does anybody have any guidance?

Edit: Booting into Safe Mode with Command Prompt will not work. See Booting in Safe Mode above.

Edit 2: I managed to boot from the Vista DVD. I ran the system repair, and now I get a black screen with white text saying:

!! 0xc0000034 !! 290/169894 (_0000000000000000.cdf-ms)

Edit 3: I ran the system repair again, and it attempted to repair my hard drive. It failed.

Problem Signature:
Problem Event Name: Startup Repair V2
Problem Signature 01: External Media
Problem Signature 02: 6.0.6001.18000.6.0.6001.18000
Problem Signature 03: 4
Problem Signature 04: 196611
Problem Signature 05: CorruptVolume
Problem Signature 06: NoBootFailure
Problem Signature 07: 0
Problem Signature 08: 0
Problem Signature 09: unknown
Problem Signature 10: 1168
OS Version: 6.0.6002.2.2.0.256.1
Locale ID: 1033

Answer: Parts of the hard drive are corrupted. All of my user's code was checked in, so I'm just going to format the box.