How can I check for hardware conflicts?

I still can't get my ATI TV Wonder to work properly! Every time I reboot, I have to reinstall the whole !&%##!!#! thing for it to work. I was wondering if there was a hardware conflict with something else in my computer. I went to the store to see if other people had any problems with this card and it seems that I am the only one... The clerk suggested that I look for ressource conflicts or something like that. He maintained that you won't be able to tell this simply by looking at the device manager and that you had use the system monitor tool that came with windows. I don't think that he was right though because as far as I can tell, this just monitors cpu, usage and stuff like that.

Does anyone know how to tell if any of my devices aren't too happy together?