"I usually just set it to go overnight and then go to bed."
Yes, that's what I do.

With BB Linux, unless you are a Linux user and want to mess around, you would be better installing Windows.
If you lost your OS with the crash, you might have a COA sticker on the PC with a serial number, so if you get the right Windows install DVD you can re-install.
You can also buy Windows OS's on eBay cheap.