Can I use Windows (XP,Vista,etc.) and install it on multiple computers with only buying 1 copy?

I was wondering if I can buy a copy of Windows XP, or Vista, and install it on multiple computers, or do I have to buy all diffrent copies for all of the computers.

Thanks,

Eddie

Can I use Windows (XP,Vista,etc.) and install it on multiple computers with only buying 1 copy?computer security

Only if you buy the version that allows multiple installations. A regular copy with one license will only be able to be installed on one computer.

Can I use Windows (XP,Vista,etc.) and install it on multiple computers with only buying 1 copy?free spyware remobal

No, you need to buy one copy for each machine.

The software creates an ID for your machine from your components - CPU, hard-disk, memory size, ethernet address, etc. It then registers that ID with Microsoft's database either through internet or dial-up.

If you use the same copy on another machine, when it tries to register itself with their server, it will see that this copy was already used for another machine ID.
You can use one copy and install it on all the systems, as long as the copy is genuine, otherwise it's illegal.
Yes and no :). If you don't have the site license, no. Win XP and above requires that you activate the software. Read here for the explanation of how Windows Product Activation works: http://www.aumha.org/win5/a/wpa.php