Quote from TGregg:
For a discount solution, you can have one PC that is dedicated to trading only, and the same PC also have games, movies and whatever else you want.
You just have two different hard drives, and you switch between them. Of course, there's the small inconvience of having to reboot each time, but if you set it up yourself, it's pretty cheap.
There's also somebody who sells a switch to do this.
It's what I do. I have my main PC that's pretty studly, and a less powered one for backup (to be used to bail out of positions if my trading PC keels over). If I want to play around, or try some new program or whatever, I close down my trading PC, switch drives, and fire it back up. Now I can run more dangerous things without impacting my trading.