and downloaded some .exe file and ran it like a fool. It was immediately detected by my av for some backdoor dropper virus. And after that i am having problems working in windows in normal mode. Everything just hangs and the mouse doesnt respond and it takes a lot of time to load the desktop. Also applications get hung and task manager also does not respond. The computer has just come fresh after a windows re-installation. I know i shouldn hav downloaded that file. But now i want to repair the system. PLease help me. I am using windows xp sp2, intel t1300 1.66ghz, 1gb ram and 80 gb hdd. I am using avast home edition v4.8.