I have been using Norton AV 2003 and last week installed AVAST Home Edition with the intent of replacing Norton after a short trial period. After installing AVAST, I got an AVAST message that since NAV was also installed, certain AVAST features could not be implemented. I have just now uninstalled NAV and was wondering if I need to reinstall AVAST in order to have those features installed that could not be installed when NAV was also installed.
Thanks in adance for your help.
Stew
Did you remove NAV using the uninstall util?
If not I suggest you do so. (Don’t forget to reboot after doing it)
Then do a repair of Avast.
Reboot and see if you still get the same messages, if not check and ensure that the avast is functioning with Standard Shield, etc running.
If you are still getting the messages about another AV, there may be stuff left behind by Norton (regular topic in these forums) - Remove Norton NAV2003, the tool can be downloaded here: ftp://ftp.symantec.com/misc/consumer/Rnav2003.exe.
If no messages but avast not fully installed, try the repair as Eddy suggested, if that doesn’t work then, uninstall, boot, install.
Let me say something about Norton X X*)(&^%$&£"$!%*X **
I signed up online for a full Norton 2004 (early 2004) package (virus / firewall etc etc). A few weeks later, I am receiving HUNDREDS of spam e-mails from the address I registered with them norton@… I have my own domain so tend to put company names at the front just to trace the very thing that happened. Norton’s response … tough … :o We got yer money!
Deleted/uninstalled the same the next day, downloaded Avast the same day (private home user) EXCELLENT EXCELLENT EXCELLENT.
Norton - Get stuffed :-[
Like any other old user of NAV that start using avast, we know what you mean ;D 
After using the NAV uninstall facility, and then rebooting, all of the AVAST functions are now operating.
Thanks for the help.
Stew
Glad to have been able to help, welcome to avast! and the forums.