The shortcut is a workaround and not a solution, you need to activate that every boot.
Complete the
avast! 4 Home Registration form and you will receive an email from register @ avast.com (without the spaces) with your registration key.
Do you use the Spybot TeaTimer as this can kill the ashDisp.exe start-up entry, the same it true if you have the paid for version of AdAware and use its AdWatch. If you have either of these disable the active protection.
Both of these should really have notified you about ashDisp.exe and asked for an action, allow or block, etc. They should hopefully have a means to restore the action taken, check and see if you can reverse it. If not, try a repair of avast. Add Remove programs, select 'avast! Anti-Virus,' click the Change/Remove button and scroll down to Repair, click next and follow. You need to be on-line to do this.
If that doesn't work try, uninstall, reboot, install, reboot.
It would probably be best to download the latest version of avast and save it to your HDD, somewhere you can find it again. Use that when you reinstall.