So, after a 5 year hiatus, I'm getting back into the Desktop support game. Back then, I'd keep the following on a flash drive:
HijackThis!
Malwayrebytes (Spybot, Ad-Aware, some program)
Updates for said anti-spyware
Service Packs for XP, Vista, 7.
What else would I want on my toolkit? I know there should be an OS of some stripe to boot from, just to ensure that we have good hardware, but which would be best for just basic troubleshooting? Anything I'm missing?

