ATI x1900xt problems??

[cslogical]

I replaced my nvidia 7800gt with a ATI x1900xt. I updated the drivers to cat 6.5 and it is very unstable. Sometimes it will reboot and start over saying I don't have any ati software installed. I'm running a 1920x1200 res. I've been thinking I have some virus of some sort since my puter has been acting up before I installed the new card. Any suggestions would be great. Thanks

 

[KJ43]

You say you "updated" the software?

Did you uninstall the Nvidia drivers, reboot into safe mode, use Driver Cleaner Pro and clean all the Nvidia information from you computer and THEN reboot into Windows normally and install the Cat 6.5's?

Also, some more information about your system would help especially what power supply you have.