http://securityresponse.symantec.com/avcenter/venc/data/w32.klez.removal.tool.html

It's free, it's up to date, it works.

There is also more information than most of us want or need, but if you want, it's good reading.

http://securityresponse.symantec.com/avcenter/venc/data/w32.klez.removal.tool.html

Some versions block protection, so you must re-install the antivirus software.

The download is small, so for anyone who hasn't been using anti-virus software or hasn't updated since October, please take a few minutes to take the test.

If nothing is found, at least you know you are not infected.