http://vlaurie.com/computers2/Articles/environment.htm
Ctrl+F: Adding or Editing Environment Variables
Do it there once and you're good.
Yes, I know how to do that--looking more closely, "Path" = "PATH" . . . I think I was confused because when I checker earlier I didn't notice "C:\Program Files\AMD\GPU ShaderAnalyzer 1.53\" in the former.
Anyway, that fixed the problem. Cool.
Now, if I could get mencoder working . . .
Or switch to Linux. =D
I have Ubuntu, but most of the GPU things are really tricky to get working.
-Thiago
Ian