How to Find the IIS Version Number?
If you want to find the version of IIS installed on your system, there are many ways to find it. Here is a simple way to find it visually.
Step 1: Open IIS Manager.
Goto Start--> Run --> Type inetmgr It should open up the IIS Manager
Step 2: Click on Internet Information Services on the left Panel of the window
Step 3: You should be able to see the version number in the right Panel of the window in the third column.
This definitely works for Version 6.0 and above not sure for previous version, but you can try and find out