[jamaa124]

have you tried the 4.5 beta version? that's what i'm using now and it works fine for me. for some odd reason, i ran into the same problem when i did the same thing to my pc. i could install 4.1 and 4.2 but i couldn't get them to work. i'm using zone alarm and windows firewall on my pc. i didn't have much of a problem with zone alarm but the windows firewall is what gave me the most problems. try the beta version and see if that one works out for you.