Well you appear to have a reasonable spec, so nothing jumps out of me there, I was wondering about a cheap PSU but you have a decent one as far as I'm aware, try using
killdisk to format the disk, it may be wise to do it overnight as it takes a few hours depending on your system, if theres a remnant of something lurking that should clear that.
As to the board I have had video slots go bad before on the board, is there another card slot you can try ? if so see if that makes a difference, if that works it would suggest the other slot may be bad, but see what happens before you bin it lol, there may be something else causing this we can't see yet.