I have seen this on two different computers now. First Malwarebytes wouldn't install - got around that on one computer by choosing "run" instead of "save" when downloading the install file. Then, once it was finally installed it would not run - just an hourglass for a second and then nothing. The viruses/malware were Vundo/Virtualmonde and AntiVirus 2009. The first computer I just did a format/re-install of Windows but I am happy to say that on the second computer once I finally got Malwarebytes to run, it completely got rid of the infection! Malwarebytes is one of the best virus/malware solutions I have ever used and I recommend it to everyone I know that has any virus/malware problems. Thanks for a great free malware solution!