Windows 7 freeze

[TZ1558]

What causes a system to freeze? My system randomly freezes and I have to do
a manual shutdown. Is this a software issue or something else?
Win. 7 home 64bit
MSI G41M-P34 board
core 2 quad 2.66
G-Skill Ripjaws 8gb 1066
OCZ 600w psu
MSI GTX550 ti 1gb
Seagate 750gb hd

 

[nickbachu]

try to reset the bios and see if it helps