Bart's Preinstalled Environment

This one's been around a bit I'm sure, but it looks pretty cool:
Bart's Preinstalled Environment (BartPE) bootable live windows CD/DVD
"It will give you a complete Win32 environment with network support, a graphical user interface (800x600) and FAT/NTFS/CDFS filesystem support. Very handy for burn-in testing systems with no OS, rescuing files to a network share, virus scan and so on."Haven't had a chance to try it yet. That could be a good thing, or a bad thing... :)