After the installation of SP0 it may happen that it is no longer possible to make any updates. Following error will be shown in the Avira update log:

“Update cannot be performed. A previous update required a system reboot which has not yet been carried out. Reboot your system and repeat the update. “

Follow the further instructions to solve this problem.

Solution

1. Disable Avira product protection: Right click on Avira tray icon → Configure Avira → Switch to Expert mode → General → Security → disable all 3 options from the “product protection”
2. Right mouse click on Start → Open Windows explorer → Organize → Folder and search options → View → Hidden files and folders
3. Enable “Show hidden files, folders, and drives”
4. Go to:C:\Documents and Settings\All Users\Application Data\Avira\AntiVir Desktop\CONFIG
5. Delete the "rebootPending" file
6. Enable again Avira product protection: Right click on Avira tray icon → Configure Avira → Switch to expert mode → General → Security → enable all 3 options from “product protection”