Welcome to the forum.
Is that two physical HDD's that you have?
Are both internals, and if not, what is the connection speed for any external?
The MOV files are probably H.264 from that camera (if I read the specs. correctly), so PrPro can edit those natively.
With any H.264 material, your CPU is at the lower end of the spectrum, though some users have gotten Quad-core CPU's to handle H.264, just not that smoothly.
With Win7-64, your RAM is just over enough to run the OS, and is very light.
Though this ARTICLE begins talking about BSOD's, which you did not indicate that you had experienced, there are many links down-thread, and the "Clean, Lean, Mean Editing Machine" link might be useful for tuning the computer for editing work. In that article, be sure to see the the links to Black Viper's Win7-64 Tune Up Tips.
If you are still getting crashes, there is an article link on "Finding Clues" and then one on "The Case of the Unexplained," that might prove helpful.
Good luck, and for now, just skip over the beginning, where I talk about BSOD's. I'm only posting the link to it, because it has many useful links inside.
Have you tried any other types of footage? Something plain Jane like DV (AVI or MOV, doesn't matter)? The Canon HDSLR material is pretty taxing stuff, but it alone shouldn't cause a total crash.
Thanks for all of the suggestions and quick replies. I have installed the 5.0.3 update. No improvement. I've also dropped in smaller .mov files (from a little handheld cam), and these produced the same crashing problem. I was able to edit those videos with CS3 on the same machine. I have tried .avi and even .3gp files, all of which cause the same error. (the .3gp was only a 2mb clip). If I select the audio track in my source monitor, the files will play and I can hear the audio for the entire clip-Premiere only crashes when trying to play video files.
The big files from the T2i will play in After Effects. I'm guessing the conflict exists between Premiere Pro and my junky video card. I don't have alot of money to put into the machine, but I'm looking at a an Nvidia Gt 440 card that supports CUDA. Is it possible that this will help my problem? What about installing additional codecs? If not, is there a free codec I could convert the H.264 clips to that would edit better with Premiere? The native support for files from my T2i was one primary reason for the upgrade to CS5.
In the future I plan on investing in a better, more modern machine. However, the projects I'm interested now only involve a few minutes of final product: basically small edits from home videos and such.
I'm guessing the conflict exists between Premiere Pro and my junky video card. I don't have alot of money to put into the machine, but I'm looking at a an Nvidia Gt 440 card that supports CUDA. Is it possible that this will help my problem?
Well, I don't think that's probably the case--at least, not the card itself. There are (likely) plenty of people using the same or a similar card, or even ATI cards without this issue. You mentioned you updated the drivers--did you get the latest from Nvidia or from the card manufacturer? Also, have you tried updating your audio drivers? Odd as it may seem, out of date audio drivers have been the source of bizarre playback issues, though usually not crashing issues.
Spending more money on a card that isn't officially supported for hardware MPE is probably not the best move right now; you're certainly welcome to try that, but I wouldn't recommend it.
What about installing additional codecs? If not, is there a free codec I could convert the H.264 clips to that would edit better with Premiere? The native support for files from my T2i was one primary reason for the upgrade to CS5.
No, don't install additional codecs. You can convert the MOVs to something like DV AVI if you want (even AME will do this), but we still haven't established what the cause of the crash is. Seeing how you had crashes with other clips (you didn't mention what the AVIs are from), I doubt that it is something specific to the files and format of them.
Do you receive an error message of any sort? Or does Premiere just go *poof*?
When you checked the Event Viewer (instructions in the above linked article), what sort of warning and error messages were you getting, when the program was crashing? Might be some useful clues in those messages.