Arien pointed me to this EULA (End User License Agreement, which Microsoft uses) vs GPL comparison. The differences are obvious and the EULA indeed has some very important limitations to it's use. Some points:
- The EULA states that only the buyer can use the software on a single PC. Well duh. You bought one copy, of course you can't fill a whole network with it, that's how Microsoft makes a living.
- You are not allowed to give away or sell your copy of the software if you got it from a reseller
- You do not own the software, so it's not yours, you license it
- You are not allowed to remotely login to the PC running Windows XP (licensed under the EULA) with non-Microsoft software (such as VNC or PC Anywhere) or you should get additional licenses. I find that pretty serious and wonder why they did that.
- There is some stuff noted about the right to automatically install software on your machine, but far as far as I can see those are only patches and updates.
- Microsoft is allowed to use data about your system and sell it to third parties (do realise they don't know who you are or where you are, just that such a system exists running that and that hardware)
- The article also states that Microsoft is allowed to automatically install software that disallowes you from viewing and copying of music and video. However this is not entirely true, the license says SECURE content, that's content you're got a license for through DRM (Digital Rights Management), the sole purpose of this DRM licensing is to limit exactly that, so it's pretty obvious that's in the EULA.
- One good thing about the EULA is that it gives you a waranty on the software (although limited) which the GPL does not at all (even prevents it)