We need to have a little more info to help you here. If you had system files damaged with the Virus sweep, it might impair AHs ability to run (like for example a damaged DirectX).
Can you post the first third of a Dxdiag report?
Also, how far do you get in loading the game? Can you get to the first loging screen or does it crash before that?
Also, before uninstall/delete of AH, make a copy of your settings folder. If it did not get corrupted, you might be able to use it again after reinstall. This can save you a lot of setup headaches.