Currently am using Avast AV and for some reason ,want to change my antivirus software,and suddenly encounter problems while uninstalling my old antivirus.Then what will be the solution to this of course without formatting my windows.Many antivirus software producers offer special tools or instructions (so does Avast).Neat and thorough uninstallation of a program,is a must as it will be less problematic .
Please note that some of the advice and tools that are linked to from here may be unofficial or from secondary sources. In case of doubt, kindly ask the producer of your previously used software whether there is a recommended removal tool, and, as a precaution, backup your system before applying any tools.
Credit: Avira Support Forum
The list starts here.
Server, "Enterprise Manager":
Bullguard 8.5: http://www.bullguard.com/support/product…/uninstall.aspx
Bullguard 8.5 Vista: http://www.bullguard.com/support/product…tall/vista.aspx
Bullguard 4.x: http://www.bullguard.com/support/product…install/4x.aspx