I work for a small company (8 people total) that provides IT services for local companies that aren’t large enough for a full time IT department and all of the techs agree that Hirens Boot CD is worth it’s weight in gold. Its got a TON of tools that have saved us hours of work in getting machines back on their feet. I don think there’s been a week that’s gone by that one of us didn’t use Hirens to get a customer’s system back up and running.
You can boot to the CD and use a ton of tools, or throw it in while you’re in Windows and get access to another fabulous suite of tools.
http://www.hiren.info/pages/bootcd