If you just installed with add remove programs then running the separate uninstaller would not hurt
How to uninstall our software using aswClear.exe:
http://www.avast.com/eng/avast-uninstall-utility.html 1. Download aswClear.exe on to your desktop
2. Start Windows in Safe Mode
3. Open (execute) the uninstall utility
4. If you installed avast! in a different folder than the default, browse for it. (Note: Be careful! The content of any folder you choose will be deleted!)
5. Click REMOVE
6. Restart your computer
there is also
http://www.revouninstaller.com/revo_uninstaller_free_download.htmldid perhaps you download Avast installer to a file where avast uninstaller would not know about it???
you can also go here and do these
What if Windows Security Center Shows AntiVir or other muliple Antivirus products installed
One quirk with AntiVir causes it to still show up in the Windows Security Center even when its been uninstalled properly. If this is the case, please refer to this article to resolve it.
http://www.pchell.com/support/multiple_antivirus_in_security_center.shtmlUsing the AntiVir Registry Cleaner
If for some reason the normal uninstall does not work, you may have to download AntiVir's registry cleaner utility to remove all traces of it from the registry and allow you to reinstall it.
1) Click on the following link and download the AntiVir Registry Cleaner to your desktop
http://dl.antivir.de/down/windows/registrycleaner.zip2) Create a folder on your desktop called Antivir and Unzip the file to your desktop
3) Double-click on the file called RegCleaner.exe to run it
4) Since the program is German, you'll have to click on the button called "keys asulesen" to search the registry for any issues. Then place checkmarks next to the registry entries you wish to delete.
5) Finally, click on the button called "loschen" to delete the keys
6) Restart your computer and try to reinstall your antivirus
Let us know if the regcleaner finds any fragments that the uninstaller missed- Thanks
I really recommend that you run an AV
PS did your machine come with any AV or Security Suite Preinstalled- that could also be the source of an uninstall conflict
If so post back