[Jimmy Cao]

It's conceivable that the .stp files from your 2 sources share a common origin, in which case I wouldn't be surprised if they're both bad.

I believe the repair utility can be accessed via either 1) Add/Remove program menu (control panel, it'll probably ask for your SW DVD), or 2) The setup program on the SW DVD (forgot what it's called). When prompted, pick repair instead of remove.

Good luck.