Remove Avira Antivirus from Windows 10 Registry

I installed this program a while ago but it caused some problems. I uninstalled it and did not experience any further problems until Windows kindly upgraded my Windows 7 OS to Windows 10. With the April update from Windows, the problem started. The update could not be installed and it came to light that there were still some rests of Avira left in the registry. I tried using an uninstaller program but the program is not displayed in the uninstaller. I then tried Windows registry editor and did find the program. However I still could not remove the program, Then I went to safe mode and tried to remove the program. Happy days it "worked". It was an illusion.
Avira does not provide a removal tool for their own product as far as I can establish. Any possible suggestions to solve this? It is also causing crashes and freeze up of my PC. Help will be highly appreciated.