HELP ASAP why does l4d2 keep crashing

[Gay Dad in the big city]

my friend recently bought l4d2 and whenever he tries to get into a game the game crashes. he tried verifying the integrity of the game cache, but he got an error that said "could not process files 101" he's lowered all the graphics and uninsalled and reinstalled the game and that didn't work. he even updated his graphics and it didn't work. Please help i don't know what else to do

Friends PC specs

Manufacturer: Dell
Model: Studio: 1555
Processer: Intel(R) Core(TM)2 duo ctu T6500 @ 2.10GHZ 2.10GHZ
Memory (RAM): 4.00 GB (1.25 usable)
System type: 64-bit operating system

he has a windows vista

[Woodi]

so it wont work before?
try to make dxdiag? Open DirectX Diagnostic Tool by clicking the Start button Picture of the Start button, typing dxdiag in the Search box, and then pressing ENTER.

http://windows.microsoft.com/en-za/windows-vista/run-directx-diagnostic-tool

[Gay Dad in the big city]

yeah

[Woodi]

maybe he should disable some tools/software he opens and not using

[Shao]

How does it crash?

[Gay Dad in the big city]

the screen turns blakc and it exits itself after a while

[Vitami]

make sure all his drivers are up to date. I recall getting this glitch and I faintly remember patching my drivers.

[Woodi]

maybe windows update can help