'Invalid License Number' error on current install.

[tkoller]

I have been running Home v 4.8 on XP Pro since last September. About a month ago I had some network issues that could only be resolved by using the system restore feature. I set it back to last October. Now I decided to run a virus scan ( my last virus was 5 years ago  ) and received the message that the registration key was not entered. I entered my key and was told it is an invalid license number. To be certain I had the right number I had it resent by avast!. Same number, same result.

Any ideas? But first let me guess, reinstall?

LOL, I just read the post before mine. It wasn't there when I first searched and then registered. So my guess is right?

[DavidR]

Using system restore can have some unexpected and undesired impact.
Check the system date is correct (day/month/year) and adjust as required.

I would suggest a clean reinstall of avast, not just a reinstall:
Download the latest version of avast http://www.avast.com/eng/download-avast-home.html and save it to your HDD, somewhere you can find it again. Use that when you reinstall.

Download the avast! Uninstall Utility, find it here and save it to your HDD.
1. Now uninstall (using add remove programs, if you can't do that start from the next step), reboot.
2. run the avast! Uninstall Utility, reboot.  If step 1 failed it may be necessary to run this from safe mode, once complete reboot into normal mode.
3. install the latest version, reboot.