for the chugging sounds at STARTUP i WOULD check all of your fans to MAKE sure they are working properly also if you have anything running in the background turn them off even anti-virus programs. I had the same problem also I agree with homer. I would like to add that Vista home Premium is just bad for a gaming machine. That OS was intended for basic, non "resource hungry", APPS. It may not add to the reason why your machine is running slow, however, it is not the recommended choice.

Vista alone should have at least 1 GB set aside to run the operating system, even if it is still just "Home" and not "Ultimate".

Check out your Task Manager to see how much memory you are using just running windows on a basic start-up. If you can, increase the PF usage on your memory, that can help with performance sometimes.

Unfortunately, I have not tried to change that on Vista yet and therfore am not sure how... Remember the key factors of how well a game operates on a comp

Mac's Factors of how well a game can perform
Quote

Processor and its speed
RAM size
OS version
3D Card or not