I got a BSOD today after getting home from 11 hours of work...

1. It seems to work in SAFE MODE (sometimes, not always)

2. The BSOD says:

   SYSTEM_SERVICE_EXCEPTION
   STOP: 0x0000003b
   WimFsf.sys - Address FFFFF88001A6B76B base at FFFFF88001A600000, DateStamp 4a5bc362.

3. Sometimes it shows the welcome screen, shows the destkop for a few seconds and then BSODs

Already did:

• unplugged all the USB devices
• reset the CMOS

I haven't installed any new software recently.

What should I do?

EDIT:
I've managed to get into safe mode and it seems to works fine. When I go into normal mode it shows the desktop then it freezes...

Is it more likely to be a software or hardware problem?

EDIT2:

I've managed to get into normal mode by disabling all the non-microsoft services & startup programs. One more thing: When I shut down my PC, on the "Logging off" screen appear some artifacts. I don't think it's because of my graphics card cause I've opened Black OPS and it worked fine. It's so strange... It still BSODS on startup (but there a ~=10% that it will not), and when it doesn't BSOD's it works fine...