Shared Folders not accessible

When I install Avast free, all shared folders on XP computer no longer available to other computers on my home network.

Did you reboot after installing avast?
Is/was there another av on the system?
If so which one(s)?
Did you allow avast in your firewall?

I had Mcafee previously installed.
The Microsoft firewall is turned off.

I have 3 computers on the home network.
Any computer with Avast installed will not allow other computers to see their shared files.
A computer with Avast installed will look at shared files on a coputer that does not have Avast installed.

I have turned off all real time shields.
I have turned off the windows firewall.
I did not install avast internet security.

Any ideas?

Presumably these computers also had McAfee previously installed, so the first thing I would suggest that you ensure all remnants are removed.

Or http://majorgeeks.com/McAfee_Consumer_Product_Removal_Tool_d5420.html

2007 version - http://download.mcafee.com/products/licensed/cust_support_patches/MCPR.exe

Also see - How do I uninstall SecurityCenter? http://ts.mcafeehelp.com/faq3.asp?docid=71525

I agree with DavidR.
Also, have you disabled “simple file sharing”?
Since avast! doesn’t block network traffic, it is most likely a Windows problem, a conflict between software or a setting problem.