I’ll teach you how to uninstall Avast 6 Antivirus with Avast 6 uninstaller program, or the Avast 6 uninstaller program which you can download from Avast 6. Even if you uninstalled Avast 6, it might not uninstalled all the left over files and registry keys in my experience, so running the stand alone Avast Antivirus uninstaller from Avast is a good idea.
You can go to add/Remove programs in the control Panel, or from the Computer Windows where all your drives are listed. Lastly, you click on the Avast 6 Antivirus uninstaller from Add/Remove programs, and follow the wizard to uninstall Avast. After the un-installation is finish, you need to restart your computer to finish the un-installation.
If the un-install failed for Avast, you can try doing a Windows System Restore to a time or day before you installed Avast.
Avast also provides a Uninstaller Utility which lets you uninstall Avast if the default uninstaller does not work, or left behind some registry keys, services, and files which it did not clean up.
The Uninstaller is called aswclear.exe which you can download from Avast.
After you downloaded the installer, you need to restart your computer into safe mode to run awclear.exe to completely get rid of Avast 6 or earlier versions of Avast like Avast 4.8, 5, etc.
To boot into safe mode, Hold down the F8 Function key on the top of the keyboard during computer start up then a black screen with “safe mode” will appear on your screen.
Select Safe Mode by pressing the down arrow, and click enter.
Login into Windows, and open the awsclear.exe program.
Pick Avast 6 or a different version if you are using Avast 5 or 4.8.
Run the program by clicking the Remove button.
Finally, Restart your computer.
Now Avast 6 should be completely removed/un-installed from your computer meaning all files, folders, services and registry keys which Avast 6 installed are deleted.
Remember to install another Antivirus like Microsoft Security Essentials, Comodo, AVG, Anti-Vir/Avira, etc if you do not want to reinstall Avast 6 Anti-virus to your computer.
Download AWClear from:avast.com/uninstall-utility to completly uninstall avast from your Windows computer.