IIS limits imposed by Operating System version

The Home/Workstation versions of Windows have intentionally feature-limited versions of IIS.
Some will only support one website bound to a single IP address and/or a limited number of simultaneous users browsing the site.

You should always use a Server version of Windows for IIS in a production environment.
 
 Windows Server 2008 R2 (IIS v7.5)    
Server:   Server OS = No Limits
     
 Windows 7 (IIS v7.5)2    
Starter:   No IIS
Home Basic:   No IIS
Home Premium:   simultaneous request execution limit of 3, allows multiple sites
Business:   simultaneous request execution limit of 10, allows multiple sites
Enterprise:   simultaneous request execution limit of 10, allows multiple sites
Ultimate:   simultaneous request execution limit of 10, allows multiple sites
     
 Windows Server 2008 (IIS v7)    
Server:   Server OS = No Limits
     
 Windows Vista (IIS v7)2    
Starter:   No IIS
Home Basic:   No IIS
Home Premium:   simultaneous request execution limit of 3, allows multiple sites
Business:   simultaneous request execution limit of 10, allows multiple sites
Enterprise:   simultaneous request execution limit of 10, allows multiple sites
Ultimate:   simultaneous request execution limit of 10, allows multiple sites
     
 Windows 2003 (IIS v6)    
Server:   Server OS = No Limits
WHS:   Server OS = No Limits1
     
 Windows XP (IIS v5.1)    
Home:   No IIS
Professional:   concurrent connection limit of 10, allows only one site
     
 Windows 2000 (IIS v5)    
Professional:   concurrent connection limit of 10, allows only one site
Server:   Server OS = No Limits
     
 Windows NT 4 w/ SP3 (IIS v4)    
Workstation:   No IIS, PWS installs as part of the NT Option Pack
Server:   Server OS = No Limits, IIS installs as part of the NT Option Pack
 
1 Windows Home Server (WHS) is essentially Windows Server 2003 so it includes IIS v6.  While WHS has a limit of 10 enrolled computers, there is no limit to the number of machines that may access network shares or IIS. For example, 1 user account could be used across 50 computers to access a share or authenticated site in IIS.

2 Does not include SMTP service.

Small Business Server (SBS) or Web versions of the OS do not impose any special IIS limits.

There is no IIS available for Windows 95/98/SE/ME but some have used Personal Web Server (PWS) which has a concurrent connection limit of 10.
Apache web server software would be another method.