If you update the OS, you can use the older version on any machine you like. Only a few languages Takes longer to become proficient. Many more than for Linux. For the inexperienced user with little real computer knowledge NT is much easier to administer and configure. Each language has a different price.
Server is more expensive than workstation.
Pay extra to allow users to access the resources on the server. Hundreds of variants in different languages and different versions. Upgrades almost as expensive as the full product Pay extra for most programms. Pay for MS-Office, pay for the operating system. Have to pay extra to allow users to access Internet mail.