Display keeps changing

My display screen keeps changing from whatever pic. we have chosen to black and white pixelated stripes. I can change it back and sometimes it lasts a few weeks other times not even 10 min. I checked my settings and properties and they are at the highest they can go. We did have a trojan that hijacked our browser last week, but this has been happening for a while. I don't know why or how to fix it. If you need to see the dxdiag i can post that, but i did not save the log files from the trojan. And the video card is an ATI VisionTek x1300 series. Thanks in advance for any help.

 

Is it just the wallpaper or background picture that gets messed up or is it everthing on the screen? Including icons and what not? Maybe a video driver update will help. Or, if you have access to another video card, try it out for a little while and see if the problem still occurs. If it does with a different video card, then you know the problem is probably software (or, worst case scenario, another peice of hardware like your RAM or MoBo).

 

It is just the wallpaper, the icons all remain the same. I am pretty sure my driver is up to date, but I will double check that. Besides changing out the video card (as I don't have another one) is there any other way to tell if it is the hardware?