I am in the same situation, bought the game, version 2.1 (Win7 64 bit, 4GB RAM), same 0xC0000005 error logged in system event (application category) with the following information:
Faulting application name: witcher2.exe, version: 0.0.0.0, time stamp: 0x4ec10073
Faulting module name: ole32.dll_unloaded, version: 0.0.0.0, time stamp: 0x4ce7b96f
Exception code: 0xc0000005
Fault offset: 0x750ef4bb
Faulting process id: 0x1a84
Faulting application start time: 0x01ccadf6609339a6
Faulting application path: W:\Steam\steamapps\common\the witcher 2\bin\witcher2.exe
Faulting module path: ole32.dll
Report Id: a1a58256-19e9-11e1-9d13-002186c44c34
An additional information entry in log, looking like:
Fault bucket , type 0
Event Name: BEX
Response: Not available
Cab Id: 0
Problem signature:
P1: witcher2.exe
P2: 0.0.0.0
P3: 4ec10073
P4: ole32.dll_unloaded
P5: 0.0.0.0
P6: 4ce7b96f
P7: 75116751
P8: c0000005
P9: 00000008
P10:
Attached files:
C:\Users\myuser\AppData\Local\Temp\WERC67A.tmp.WERInternalMetadata.xml
C:\Users\myuser\AppData\Local\Temp\WERD4DC.tmp.appcompat.txt
C:\Users\myuser\AppData\Local\Temp\WERD7CA.tmp.hdmp
C:\Users\myuser\AppData\Local\Temp\WERDAB8.tmp.mdmp
These files may be available here:
C:\ProgramData\Microsoft\Windows\WER\ReportQueue\AppCrash_witcher2.exe_eb3cabe8d9529e0d21a7369f47dc8c88cd864b8_cab_13f0db32
Analysis symbol:
Rechecking for solution: 0
Report Id: 9e4663f8-19e9-11e1-9d13-002186c44c34
Report Status: 36