What bootable software tools do PC techs use for PC troubleshooting? ..if any. I know in OS X it's very useful to boot form a bootable OS X hard drive or SSD with some tools. Not sure if this is done with PCs (perhaps because the needed drivers for all PCs can't be put into a single bootable Windows, I don't know). I heard about Hiren's boot CD (not sure it's legal?) and Ultimate Boot CD, not sure if they're good at all.