In a Microsoft article I've found this solution:
"If more than ten connections are needed, use the version of IIS 5.0 that is included in Windows 2000 Server."
I've tried that a few times with no success. I still cannot increase amount of concurrent connections.
Yes, I've been seeing about 1 request per minute from Nimda infected systems, and I don't expect this to change--ever. However, I hadn't thought about how it would affect user-limited IIS implementations.
There is no legal way to change that limitation--it's more a licensing
restriction than a technical limit. There are other free Web servers
for Windows that don't have the limitation, however I haven't personally
worked with them. The most popular Web server on the Internet, Apache,
is now available for Windows. Good luck.
This was first published in October 2001