If you ask me, i think the industry need a Standardization Bureau or something. God Damn IT!  Why is it i have to struggle to find the version of IIS. You would think that you could just go to  “About Internet Information Service” in IIS manager and locate it easy but then again basic information keep changing location from one version to another.

That is why i have done a little research and compile that list below:

Windows Server 2003, you are running IIS 6.0
Windows XP, you are running IIS 5.1
Windows 2000, you are running IIS 5.0
Windows NT 4.0 or Windows 9x

    ‘ returns “Microsoft-IIS/4.0” for IIS 4.0 + ASP 2.0

Do a search for ASP.DLL on your system
right-click it and select Properties
Check the version tab:

IIS 3.0 shows 1.x
IIS 4.0 shows 2.x
IIS 5.0 shows 5.0.2195.x
IIS 5.1 shows 5.1.2600.x
IIS 6.0 shows 6.0.3790.x

This Script Below should give return the version of IIS you are running.