Alan Zisman -> All said the following on 5/30/2012 12:54 PM:

 AZ> Google check for 'ransomware removal' got a Microsoft utility
 AZ> that worked to remove the infection.

 AZ> However, it didn't cure some side-effects of the infection...
 AZ> there were a couple of AV programs already installed: Avast
 AZ> and MSE... neither would open up and run; reinstalling didn't
 AZ> help. I tried installing AVG and AVIRA - neither of those
 AZ> would run either. The AVG installation repeatedly failed.

Did you (or can you still) try the free on-line scanner called HouseCall
(by TrendMicro?).   It has worked for me quite well on several ocassions.

Another wonderful tool is Malwarebytes.  Boot to Safemode with networking. 
Get the latest version from the internet, install it and let it scan.

--- Thunderbird 2.0.0.24 (Windows/20100228)