True, you don't need any additional software to do this 'cos WinXP's Remote Desktop can do it for you generally. But what if,
* the comp ur on and the comp u wanna get to cant make contact due to being buried in different subnets.
* ur on a mac and you wanna access your WinXP comp. (btw macs can access windows shares easily)
* ur on a version of windows other than XP.
Solution? I hunted for a few but this is the best option in my opinion - just go LogMeIn.com, all of these work! You have to install software on the comps you wanna access but after that it's a breeze. All you need is a browser and an internet connection! It runs off an ActiveX control or Java, whichever you want. It's pretty quick, but not as fast as Remote Desktop (cos LogMeIn runs across the net I guess?) but c'mon it's free!!
LogMeIn Pro is awesome but the trial only lasts for your first week of usage, after that it's the free version (which works just fine too, minus the bells n whistles). So if u really wanna enjoy the Pro version, dont install it until u need to use it:D
[tried and tested across different networks in NUS - it works haha]