Here are a few tools I use when computers are behaving quite right.
NirSoft ProduKey – recover many Microsoft Product Keys
Windows Offline Password Recovery Tool – reset and remove user passwords by booting to live CD
Ninite – install the most popular open source software with a few clicks
USBuntu Drive – I used LinuxLive USB Creator to make a bootable version of Ubuntu. This is great for those computers that won’t boot but you need to recover files from
Process Explorer – Identify all processes and easily terminate them. Super handy for those hidden malware programs