Jim, thank you for your answer, although as a non IT person, I had difficulty understanding. I did find a Klez removal tool at Symantec and did use that in safe mode so hopefully it is gone. Now I am going to try to install AV4.
I had kept AV3 up to date. As a matter of fact, it was just updated yesterday. Is this something that Avast misses?
Jan
No, Avast! is a fine AV, and should (and does) catch Klez, however, (who knows) maybe the resident monitor didn't load for some reason, or had some other glitch.
In addition, some variants of Klez stop the processes and delete files associated with antivirus programs, so when you opened that attachment, you might have "killed" Avast.
You did good! I dealt with Klez yesterday, in fact, and needed to run Avast! get rid of it completely. A scan running in Windows would not completely remove Klez, because it was also located in the Windows .swp file, which is in use while Windows is operating.
If you got a clean bill of health using the removal tool, I would re-install Avast! 4 and do a manual scan while in Windows.
If you get a clean scan, (and the "little blue ball" is down there doing it's thing when Windows comes up after reboot) I would say you've probably cleaned up Klez.
Good luck!