@
Navvy and
kryptonNavvy first, try a full install from scratch. Go
here and download the uninstall utility (aswClear5.exe) and save it to your desktop.
-Have the install file you had previously downloaded handy, on the desktop or a flash drive.
-Disconnect from the net
-Right click any Avast tray icon, locate "program settings>troubleshooting" and disable the self-defense module.
-Uninstall any (and all) Avast versions from "add/remove programs" in the control panel. Note, you will lose any settings and quarantined items. Reboot- see next item.
-Run the uninstall utility. If there were problems with the uninstall, this should be run in safe mode. Reboot.
-Install Avast from the new installation file for 5.0.545. Reboot as prompted.
-Reconnect. Open the Avast interface, select "maintenance>registration" and fill out the required fields to register Avast.
You may wish to manually update the definitions, if I remember correctly, the program may have already done that as part of the setup. Let us know if that worked/didn't.
krypton
You will probably have to install the flash player for IE if you only have it installed for another browser. I've had that with other programs in the past. See if that works.
All the best.