Hello,
If your OS is Windows Vista (Premium and above), then consider following things.
You can not install IIS with Vista Home Basic.
Can you see IIS services as part of Windows componants installed? or
Start -> Run -> inetmgr (Enter)
If IIS is installed on your machine, it will open IIS Manager.
If not, you need to install it through Windows Componants (you will find it in Control panel -> Add/Remove Programs)
After successful installation, try and run 'inetmgr' through command prompt.
It will open IIS Manager for you.
Hope this will help you..