#1

Increasing IIS connection limit

To increase the crappy limit of 10 concurrent connections to IIS (maximum allowed is 40 - which is the hard-coded limit) on Win XP, you can perform the following:

Find the adsutil.vbs script (should be in c:\inetpub\AdminScripts or similar) and run the following command at the command prompt:
adsutil set w3svc/MaxConnections 40
You can also download a utility that alters tcpip.sys from http://www.lvllord.de/. The app can be detected as a virus with some Ant-Virus software when it is not.

#2

You can also do the following in a command prompt:

cd \inetpub\adminscripts
cscript adsutil.vbs set w3svc/MaxConnections 40
iisreset

#3

You can also try to prevent individuals from hogging a bunch of connections and thereby blocking out other users. (IE will normally use 2 connections to a web site.) To do this, launch the IIS admin tool (under control panel / administrative tools), right click on your default web site (under web sites in the outline control), and mess with the settings in the connections part of the web site tab. Lowering the timeout (default is 5 min) will cause idle connections to get dropped quicker. Disabling keep alives will cause connections to disconnect immediately after the request is handled instead of waiting for new requests on the same connection. This is a little extreme but you probably dont care that much about responsiveness, so you might want to just try that and see if it solves the problem.