It's better to have a separate computer for your RIP/Film needs rather than hog the resources on you main computer.
Get a cheap laptop on craigslist and load up XP SP 2, turn off updates and only load up the RIP software. Keep it as bare as you can to improve the performance as XP only uses 4 gigs of ram.
If you're really computer savy, you could run a virtual box inside of Win 7.