A while ago I mentioned in another thread that since installing Avast I could no longer access shared folders on my home network. Apparently this problem isn’t only caused by Avast but some other AV packages as well. Anyway I finally found the solution and thought I would post it here in case anyone else finds they have a similar problem. Using regedit either add the following key (or change the value if it already exists). HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\LanmanServer\Parameters\IRPStackSize Add / Change value of key to decimal 18 on the machine with the shared folders. There is some more detail here: http://support.microsoft.com/kb/177078 But please note the value needed to make it work for me is DECIMAL 18, not necessarily the ones stated in the article.