Windows 7 Computer freezes after 15-20 minutes of gameplay in CoD4

[PrPrO]

Hy,

my computer freezes enterily after 15-20 minutes of playing Call of Duty 4, so, nothing works, nor alt+tab or ctrl+alt+del
it worked fine for sth. liek 1500hrs and started to freeze 3 months ago
my configuration:
graphic card - Nvidia GeForce 9800GT
procesor - Intel Core 2 Duo CPU E6750 2.66GHz
power: PRO-550 - 550W
memory - 4Gb Kingmax DDR2(1x2Gb, 2x1Gb(some different specs))

can You please help me?
Thank You in advance

 

[PrPrO]

[langtitle=it]Re: Computer freezes after 15-20 minutes of gameplay in CoD4[/langtitle]

[lang=it]it si freezing in CoD2 multiplayers, too[/lang]