>> the windows will run the same like on a normal pc with the same configuration but why to buy a mac if u use windows ?
The reason: dual booting. A lot of people would like to have the flexibility of having both OS in one system , if possible. With intel based macs, its now reasonably staright forward, see the following topics:
http://nirlog.com/2006/03/18/winxp-a...n-macbook-pro/
for more details, try the excellent site MacOnIntel.
http://www.maconintel.com/