Ten days ago I added a post that complained that my PC wouldn't boot and may be crashing. Last August I bought an emachines T3616 desktop PC w/AMD Sempron processor 3600+ and Windows Vista Home Basic OS. Well, I have been having on-again, off-again problems with booting. Today my PC started up normally and Windows Security Center detected NO antivirus software. So I began to download AVG Anti-virus Free Edition but when the download completed an error message stated that it was a corrupt file and that I should download a clean copy. When I tried closing the window another message said a cord was not connected to a Local Port. Should I attempt a second, clean download and see what happens? I don't know what I should do. Any help is appreciated. Thank you.