I installed build 2031 of Windows 2000 (which I shall refer to as Win2K from now on) about two months back. I am in the process of moving over to the newly released RC 1, which is build 2072 (release candidate 1). So far the differences seem to be more drivers and under the cover bug fixes as well as quicker load times. The screenshots I have included here are from build 2031. When I got the Win2K CDs I was very keen on trying out the FAT32 support that it comes with. I think a lot of people will run Win2k alongside of Win9x at least till a service pack or two. Another reason why you might want to do this is because there are many games that will not recognize Win2k (even though it ships with DirectX 7) and therefore refuse to run.

I partitioned my drive into two partitions, one each for Win9x (Win95 OSR 2.1 in this case) and Win2k. 
I then installed Win9x and after getting the basic configuration going, installed Win2k on the other partition. The installation process was pretty much automated to begin with. If you have a bootable CD-ROM, you can enable the feature, put the CD in and restart the machine. This is what I did and it went about installing after asking the basic questions about which partition I want to install it on. It also gave me the option of repartitioning my drive and formatting the partitions as well. After this point it went into automatic for quite a while. Upon restarting on its own, it went through a hardware detection process similar to the "add new hardware" thingy with Win9x. Next, it asked me for details about myself (passwords etc.) and computer information such as time zones. What was missing was the usual option screen you get when you install Win9x. Having got to the new Win2k user interface in the second reboot, I realized the setup program had installed more or less everything. All the accessories and communication options etc, were there. In the [control panel -> add/remove programs -> add/remove windows components] section, all I discovered was stuff like IIS and FrontPage extensions.
 
 

The next thing I did was to try and run a Direct3D game. I grabbed the one nearest to hand, which was NFS 4: High Stakes. No luck! It refused to work since I don't have Windows 95 or 98! I then tried Motor Racer (an old mobike game). It installed without incident but refused to recognize DirectX as being present. I think the biggest problem here is that DirectX versions which ship with Win9x have version numbers which read 4.x.xxx (where x is the major version number and the xxx is the revision) while the leading 4 is replaced by 5 in Win2k. I haven't tried too many games since but the only thing that I have played on Win2k so far is Heroes of Might and Magic III. Sadly non of the graphic card drivers I have give OpenGL support in win2k. This would have let me play Quake 3 Arena.