i had a a trojan and was able to get rid of it , but ever since then i have a problem opening up any function of my computer. whenever i wanna do something or install something i have to go thru a window that says open with, and it shows diferent programs to open it with trouble is that sometimes the program doesnt match what i have to open, and it doesnt let me install things. i did a system restore i went back as far as i could go and i backuped files on a external drive what else can i do to fix this problem? im operataing on a compaq presario with windows vista. thank you very much for your help.