I've had the best luck with Symantec's fix proggie just make certain you follow the directions and run it from safe mode. Klez attacks .exe programs in your start up hence programs like Norton AV not running properly. You know your clients have klez when they call and say my Quickbooks isn't opening or I can't start Norton etc.
I've had two systems that were so far gone I had to reformat, one wouldn't even boot into safe mode.
You can get the Norton fix tool here along with the directions and a digital signature verifying its authenticity.
You can get the Outlook patch here.
If you're working on a system that has Norton AV installed on it and it's unable to update due to Klez, you can reinstall and be prepared ahead of time by having downloaded your virus updates via intelligent updater. Obvioulsy, do this from a clean system and have it burned to a cd. You do not want the infected system on the network while your doing the clean up.
Hope this helps,
TC
