Just downloaded AVAST free 5.0 and computer is very slow

[shortre]

I have a laptop that is from my school district and has CA installed already.  Even with that, I got viruses and had to have it re-imaged twice.  A tech said to use avast.  As soon as I installed it, my computer is running very slowly.  Explorer will not go anywhere and Outlook has not responded.  Do I need to uninstall CA or something else?

[DavidR]

Yes you absolutely need to uninstall CA as two resident scanners will be fighting over the file to scan and aside from duplication of scanning are very likely to conflict.

After you uninstall CA, reboot and see if that resolves the problem. It may be that you need to run another uninstall tool to ensure all remnants of CA are gone (if you still have problems).

Also see http://www.askvg.com/ultimate-collection-of-uninstallers-removal-tools-for-all-popular-anti-virus-software/ for others not listed above.
and http://uninstallers.blogspot.com/