Avast disabled after downloading

[xenon]

Using my laptop for this message as my PC running WinXP where the problem is, can't be used. While on-line my Avira AV and Malware bytes program were both inactivated by something.  I could not repair either, so uninstalled them and loaded Avast Free as it works well on my laptop. Download and initialization went normally. I started system scan which started but then began slowing to almost nothing.  I can not end or stop scan.  At the same time all 8 shields on Avast were disabled.  I can not re-start them.  Tried re-boot--still the same.  Any suggestions for getting Avast running and finding the offending agent? Thanks

[SHARKY7SHARKY]

Using my laptop for this message as my PC running WinXP where the problem is, can't be used. While on-line my Avira AV and Malware bytes program were both inactivated by something.  I could not repair either, so uninstalled them and loaded Avast Free as it works well on my laptop. Download and initialization went normally. I started system scan which started but then began slowing to almost nothing.  I can not end or stop scan.  At the same time all 8 shields on Avast were disabled.  I can not re-start them.  Tried re-boot--still the same.  Any suggestions for getting Avast running and finding the offending agent? Thanks

It maybe Avira, try a search for any left over crap that Avira may of left behind & delete. Also if you know how to check the registry do so for any signs of Avira, if you do not know how to check the registry you can use Eusing a good free Registry cleaner. CCleaner is also a good Tool to have.
If you cant delete any Avira try in safe mode.
I would use Avast removal tool & reinstall Avast after.

[CraigB]

Run the avira removal tool from here http://thewebatom.net/uninstallers/security-software/ number 4 in the list, run the tool after a normal uninstall via remove programs and then reboot.
Now go to remove programs and click on avast as to uninstall, when you get the popup screen scroll down to repair click and ok, if this does not fix avast you will have to do a clean install of avast in the way of downloading a fresh copy and saving then uninstall your current version of avast and reboot, run ccleaner ( cleaner and registry ) and reinstall your copy of avast.