On-Acess Protection will not start

[{{JM}}Angel]

I went away on a trip for about a month, leaving my computer at home in the care of my parents. When I arrived home, my computer was a complete and utter disaster. While I was away, my avast had expired, and instead of renewing the registration key as I had instructed in case it happened, my mother uninstalled avast. I had malware, spyware, adware, and every other kind of "ware" having a party on my computer. Today, I reinstalled avast and entered a registration key, thinking that everything would be fine, until I noticed the the red cross. My on-access protection absolutely refuses to start. It won't let me adjust the sensitivity of the scanner, start any of the seven providers (such as instant messaging or e-mail), and I am completely clueless as to what to do. Can somebody help me, please?

[DavidR]

When your parents uninstalled avast, did they install another AV. The red cross you mention could be a classic sign of another AV on your system.

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.

What is your OS ?
Are there any warnings or errors displayed ?
Is there anything in the avast log viewer ?

I hope you sent your parents to bed without any tea

[Lisandro]

I would suggest you schedule a boot time scanning with avast.
And, that you install and run www.ewido.net 

[{{JM}}Angel]

They did install another AV. It was a real whack-job of a program with an incredibly rediculous name that I'll bet did more harm than good. I uninstalled it before I installed avast, though, so I'm not sure that I understand why it would cause conflicts unless there are traces of the file still on my computer.

Repairing the file had didn't affect the on-access protection at all. It works when I run a system scan, but that's about it. I'll try rebooting, but if that doesn't work are there any other suggestions?

[stevejrc]

They did install another AV. It was a real whack-job of a program with an incredibly rediculous name that I'll bet did more harm than good.

Was it Norton? LOL

[DavidR]

They did install another AV. It was a real whack-job of a program with an incredibly rediculous name that I'll bet did more harm than good. I uninstalled it before I installed avast, though, so I'm not sure that I understand why it would cause conflicts unless there are traces of the file still on my computer.

The problem comes when avast finds any remnants of a resident on-access AV, this can be registry keys, to avoid possible conflict with another AV avast may disable elements to avoid conflict.

So in order to track down these remnants or find a manual uninstall solution we really need to know what it was.

There are registry cleaners that should be able to remove redundant registry keys/values/data, etc. These can be as much of a pain as they are a help so it is advisable to use one that backs-up any deletions it may make so they can be restored. It is also helpful if they categorise the stuff it finds, safe to remove, etc. A forums search for registry cleaners returns many hits.

This is just one http://forum.avast.com/index.php?topic=21847.0 RegCleaner gets a few mentions.