Windows 2000 seems to be the perfect Windows version to use on the eee pc. It meets or rather surpasses all the system requirements for it while it is just fast enough for Windows XP. Most current Windows programs will run on Windows 2000 as well as Windows XP, so why waste resources on bloat? (People used to complain about Windows 2000 bloat as well, when it was released, I guess that never changes.)
The hardware works fine, apart from the webcam.
Assuming you have got an external USB cd rom drive (I used a TEAC CDW28PU), installing Windows 2000 on the eee pc is straight forward. Just get an installation cd with service pack 4 slipstreamed and boot from it.
You say you don't have such a cd? Unfortunately you apparently need SP4 for it to install from a USB cd rom drive. But do not despair, nlite comes to the rescue.
To get the eee pc to boot from the cd you must press Esc on startup. You will get a list of devices where you can select your cd rom. After that it is just a straight forward Windows 2000 installation.
You will want to delete all existing partitions, so you will lose all your existing data (If you haven't made a backup, now is the time to abort the installation and make one!), and create one big NTFS partition.
(I got a BSOD when it tried to reboot after the installation. I just turned the eee pc off and on again and it booted fine.)
(I have had the problem that the Windows Install did not recognize the USB CD-ROM, although the EeePC had booted from it. I worked round that one by copying the whole Windows CD onto a USB PenDrive, booting from the CD-ROM and launching the install from the PenDrive.)
Once you got to the desktop, you will need your Asus driver dvd. Even though it says it is for Windows XP most of the drivers will also just work under Windows 2000. Unfortunately the Asus installation tool will not work, so you have to install each driver separately. (Here is where I run into the first problem: I didn't have an external dvd drive, just a cd drive. I worked around that by copying the drivers onto an USB thumb drive and installing from there.) Alternatively you can get the drivers from the Asus homepage.
Some drivers rely on other drivers to be installed first. Unfortunately I don't quite know which was the correct installation order since I run into error messages and had to backtrack several times. So here is the order as I remember it:
Annoyingly most drivers required a restart.
The acpi drivers won't install, but I could not find anything wrong without them.
Drivers for the webcam are available from http://www.empiatech.com.tw/support/IC_drivers/PCCAM_WHQL_Standard_Installshield_072007.zip (you get there from the main page via the flash menu by selecting “support”), but they didn't work for me. There is still an “unkwown device” in the device manager which I assume is the webcam. I have disabled it so it won't trigger the “Found new hardware wizard” system startup. (Actually, it might be a good idea to disable the webcam in the bios if you don't use it. This might save some battery power.)
A full install (I did not remove anything with nlite and ended up with an installation iso of around 355 MB) requires 824 MB on the SSD, excluding the sawp file, which I set to another 256 MB. By removing some parts with nlite and using ntfs compression this can probably be reduced further. See the tipps for Windows XP since most of them also apply to Windows 2000.
If you search the forum for “Windows 2000” you will also quite a lot of posts, some dealing with installing without an external cd rom.
Also, mackerel wrote a quick guide (which I unfortunately did not find prior to writing my own here) http://forum.eeeuser.com/viewtopic.php?pid=24908#p24908