Problem with ASUS GeForce 7600 GS 256MB

hi all i recently bought GeForce 250GTS 1 GB and gave my old card GeForce 7600 GS 256MB(PCI-E) to my brother to use it the card was working fine for almost 2 days in his computer but after that windows xp did not booted properly the windows xp xrasses after its loading i went throw safe mode then it workde fine i removed the driver and tested it again in normal windows mode it worked fine but i tried to install the drives then the system crashed now i see multiple colors in thes places

1 CMOS
2 windows loading screen

the multiple colors i see is yellow and brown.....

i dont know what is the problem in my brothers system i did not tes the card in my my sytem becos i don't want to spoil my system.....

now my brother r is killing me i made him a promise and its gone now please can any one help me to fix this problem thanks.....

thanks for replying i tried it but no use....the smae thing happneg i am installing (186.18 desktop winxp 32bit english whq)driver for my card in the list it says it sappots
GeForce 7600 GS but i realy dont know what is the problem is