We had just replaced one of our desktop units and the boss wants to be able to run an host a website on it without changeing the OS. Is it possible to set it up to do that? Like would I still change the DNS an IP like I normally, would or do I need like additonal software.Without knowing the OS he has, the answer is , No, he can't.

Way does he need website on a local machine?
What is the intended use?
One does not need a web site to serve files to other local machines.
If you really what a web presence, it is best to just rent web space.

A local college might run a website on a local machine as an educational tool. But a business would not waste resources on a local server website.

Windows 8, but, I dont know what for copy

Its so that its fast enough to host the site an not have to have another unit do just the hosting. Which, is what I WANTED to do an sold him a copy of web sever 2008.

Geek you'd be surprised

Its a more modern an faster unit, I cant say any more about it till Im back in thereOK. So he wants a web server.
Windows 8 is, in general terms, a Desktop system that can can used for a variety of applications. Including use as a web server.

My point was that a typical small business would not leave a computer on 24/7 unless they had enough workload to justify the ADDITIONAL costs.

However, you did not say it was a small business. I just made an assumption.

A reliable web presence, if that is a high priority, can be rented for under $10 per month, at a remote location which has its own routine MAINTENANCE. The amortized cost of running a quality web server on your own location is more that $10 per month. That is why I asked about the intent. A local server is best suited for local file sharing and Intranet, not Internet service.
This may HELP explain what I mean.
http://www.hcidata.info/inet.htm
Internet, Intranet, and Extranet terms explained




Right, however, this will be on all the time

I thought that it would just cost for the DOMAIN name