Originally Posted by LeonK
Thanks for your suggestions!
1. Nothing is overclocked
2. Iīll check voltages soon.
3. I think PSU has enough power, becouse the system allready worked with 32 bit windows 7..
4. Memtest86 was allready running about 2 hours, no errors.
Could it be Software problem?
Ok, what is the power rating of your PSU? Please give the 12V amp rating, brand, etc.