Chances are, the only way to get PC games on PSP is either to find a PSP port of a PC game (i.e. a game that has been converted to work on PSP, like Disgaea or Valkyrie Profile Lenneth which were originally PSX games), or you'll have to find a homebrew version of that game. Homebrew games are generally built from scratch, so they're not likely to be 100% stable, or 100% like the game on PC, and updates only become available when the homebrew author gets around to making one.
PC code and PSP code are different. PSP may have the specs to play some PC games, but that doesn't mean it can run PC code.