What happened between yesterday and today?
The computer shutdown before closing the PPro file.
Should I reinstall the CS3 Suite to another HD or something?
The backup copy of my edited video opens in PPro 2.0, but when rendering, gives an error message:
Thereafter, Ppro 2.0 closes.
This ARTICLE might help you to help us.
This ARTICLE might help you get some clues on why your program/system crashes.
Also, think back to what might have changed. As Harm points out - something has.
I'd also look into all video and audio drivers and update those. Even a simple OS update can make those obsolete instantly.
Just an example of what can happen between yesterday and today.
I installed a new Bios. No problem. I then tried setting my disk configuration from IDE to AHCI. Problem: keyboard hang. I could no longer get into the Bios to revert to the previous setting, because the keyboard no longer worked. Solution, reset the CMOS/Clear RTC RAM by moving a jumper.
The lesson is, it may be anything that happened, even if far removed from PR.