Rendered Image can't be saved

Hey guys,

I recently had a weird computer restore that happened automatically when one of the kids turned off the computer by using the power button. The PC went through a whole battery of "fixes" and finally got itself up and going. I later found that it appeared the registry had been changed such that certain programs would not even run. Nxt was one of them. Fortunately I removed and reinstalled the program and everything seemed to be OK. The rendering stuff works fine with one (so far) exception. It won't let me save the rendered image.

Attached is the warning error message I get. Please help me out with a fix. I have also included one that shows up with my other issues. Don't know if it's of any value but it can't hurt for you to see what's going on.

Thanks again,

Chris