BartPE is basically Windows XP stripped down to the bare essentials. You can add all kinds of plugins - like Firefox, to make it a semi-functional desktop, but thats not really it's purpose. It's purpose is to rescue borked OS's.
You can run adaware and virus scan utilities from it to scan hard drives for viruses and spyware and other nasties that would be hard to remove if you were booted up to the OS.
It has networking support, so you can boot up and map to a network drive to dump data off of the hard disks. I've used it a couple of times to fix peoples PCs that were badly infected with adware.
Other usefull thigns you can do, are scandisk, and defrag with dirms.
It really does make a fantasic recue disk. FOr rescuing windows, it's much better than using linux since you get native read/write NTFS support.
