brickboo, No need to reinstall it. All You need is to start the Avast from Start menu, and it will open window asking for serial number (there just Copy-Paste the serial number from the e-mail received from Avast). Absence of spinning ball (actually it doesn't spin all the time) might be some problem with installation (unstarted service or something like that). Also take care to uninstall AVG (or any other anti-virus) since there is no use to have more then one(and it's often dangerous because they try to 'desinfect' each othes virus database, making them useless).