Well, I have Windows 2000 without IE and heavily reduced on my working and home computers (7). Working fine for office needs and my home purposes. I introduce it to some of my friends and know for sure there are a few more computers out of here are running Windows 2000 without IE

But I was interested in WinPE and BartPE enviroment at the beginning of this year and I found that XP can be run complitely in RAM after some modifications. It can be loaded from CD or USB device like BartPE build but much faster and more flexible cause you can do with it everything you want to do with a full OS. It's amazing and I liked the feature very much!
Unfortunately running XP in RAM needs some reducing (working system shouldn't be bigger than 500MB - when using NTFS compression it could be a bit bigger but still need reducing from the full installation). And it's a hard task to reduce XP and leave all the features I want without bugs.
I tried nLite, xplite and Windows Fundamentals for Legacy PC's (made from XP files) - all of these methods are good but have some drawbacks... Unfortunately there is no FDV's fileset for XP like for W2k

Maybe even XP has some drawbacks for me comparing with W2k.
(Note: W2k can be run in RAM too but it needs a commercial driver that has, I'd said, a very nasty limitations so I don't like it. I don't mind to pay for a program that I like but as there is no such program and we have a "free" solution with XP, I'll try to use it.)
By the way, Windows Fundamentals for Legacy PC's is really interesting. If you have a chance to try it - do it! It's nearly the same as XP Home Edition and work fine on old computers. You can choose to install or not IE, Media Player and some other features. I'd like it for my purposes but M$ made it based on WinPE2003 that let me have at least a separate installation CD and a lot of memory on a computer for installation (not sure, maybe not less that 512MB). I still don't exclued it from my choices and myabe I'll use it for RAM boot with some modifications.
I tried Vista - interesting but I'd better install Linux if I have to change my OS
I tried Linux (one was pre-installed on a new notebook) - very interesting but maybe I'm too old to learn new things

And there are some problems with Wi-Fi on Linux yet... Maybe I'll give a try to other distributive in the future, I personaly like Slackware cause it's very customizable