My computer goes to sleepmode in assasins creed 2

[ccolijn]

my computer goes to sleepmode in assasins creed 2 and Settles 7 demo after about 12 minutes. It s very anoying, the computershuts down completly and I have to restart again and agian. This is in Windows 7. Today I looked at Settles7 demo and it was the same every 12 minutes the computer goed in sleeping mode
I read about this in other forums as a bug in Windows 7 but nobody has a solution? Anyone here?

 

[ccolijn]

this is not working for me. It is an error in the software of the geforce adaptor, in in other desktop with an ati adaptor no problem

 

[ccolijn]

a software update for geforce solved the problem for settlers 7 demo where it happened too, i have a geforce 9600m GT in a HP laptop. So thanks all for suggestions