My brother installed a software last night ( Kaspersky Internet Security ) while Avast! (beta) was on for some unknown reason and it automatically tried to uninstall it while it was on corrupting it. so i tried system restores, safe mode deletion and pretty much everything. then when i deleted all traces of Avast i installed avast again and this time it wont update, its version says 4.7.1147 like its the beta/regular version. so is there ANY way to fix this or am i doomed to use the OS disk.