But not a M$ patch - KB893066 limited TCP/IP connection from 50 down to 10 and problems as yours have been occurring - Get the patch and details from here:-
Recently my WinXP auto update downloaded and installed 4 security updates. One of these updates was KB893066. Immediately after installing, I was not able to access Win Update web site and unable to sign into my health coverage web site. For WinXP update, I was getting an error message and my health coverage web site tried to load but timed out. I also had trouble accessing links on my IP web site. After restoring my system to an earlier date and using the process of elimination, I discovered WinXP Update KB893066 to be the culprit.
Has this happened to anyone else?
I am told the problem was because of my anti-virus. KB893066 was uninstalled until a patch is offered.