I am not a tech person, but have much "trial by fire" experience. Dual boot in some cases causes conflicts in the "registry". No matter how many times you edit ("REGEDIT") in the command prompt, the propensity for the problem is still there. From what I understand, WIN 2K is nothing more Win NT with a better GUI (graphical user interface) and enhancements like USB compatibility. I have several PCs on my network, with different OSs (WIN2K, XP, and even a WIN98) Never a prob with WIN2K, except for MSFT Office 2000 Pro bugs. I use RealTick front and back end with WIN2K. No problems. I would either have different PCs, or go WIN2K. Again, I trade and mentor, Im not a tech guy. Either way, never upgrade. Copy your files, then do a full blowout of the drive, scandisk, then re / new install. BTW, check with your platforms "geek squad" (tech support) they may have some / more bugs with the OS you want to go with. Ask them first. They may say, "We've had less issues with WIN "X". The PC's primary use is trading, and that should be the deciding factor.
Some things are relatively obvious, like the indexing service. Others you can find listed on various web sites. I unfortunately do not have a URL handy but you can probably find the stuff on Google. Registry conflicts - You should not have any if you install the 2 OSs into different folders or different drives, which you DEFINITELY should do. 2000 is not just NT repackaged. There are quite a few improvements to 2000 relative to NT 4 (performance, stability, etc)
I agree, eventually more and more hardware will not support W2K. But for now it's real easy to find hardware that does and so I'll continue. Like I said I used my beloved NT (sniff...) for 4 years and only reluctantly gave it up because it could no longer do things like support multiple video cards, support USB and Firewire, support FAT32 partitions, etc. I know that there were some utilities and workarounds, and I suppose I could have extended my use of NT, but the writing was clearly on the wall as that list of things got longer. W2K solved all the above problems and until it's "list" starts accumulating I'll hang on to a trusty and thoroughly proven friend.
My rec is to not upgrade just yet. 2000 is very stable and will be around for a couple more years - until 2006 I believe when MS cuts off all support. During the interim time Linux systems will probably evolve into more economical choices than MS - unless they change their licensing terms which they may be forced to do . Until MS changes the licensing model stick with 2000. XP/XP pro only offers small performance improvements and in most scenarios essentially no improvement, but adds onerous licensing requirements, and some software compatibility issues. When buying a new system make sure it supports both 2000 and xp - most dell systems are sold with both options and are compatible. Dont bother with an upgrade unless you are being forced to by a software vendors requirements - which is unlikely since MS no longer has the stranglehold to dictate to software ISV's and many are building Linux compatible solutions as well as new generation MS systems.
I went the upgrade route a few months ago - from Win 2000 Pro to XP Pro - and have been happy with the result. XP Pro is a little quicker on big data crunching operations (or so it seems to me) and is a lot quicker to start and stop the OS. I used the blackviper set of tweaks and dropped most of the cutesy features.
I have used both, XP Pro and Win2k. Both were extremely stable. When I first upgraded from Win98 to 2000 I thought I had died and gone to heaven. So when I got a new comp with XP on it I thought I would "downgrade" to 2000. But I have really liked XP Pro. It is much easier to deal with drivers in XP...almost every piece of hardware I have installed works flawlessly on the default drivers. Multimonitor support is much better (mainly because all of my cards worked with XP, whereas I had some compatibility issues with 2000). Also, networking has been much easier with XP. But I am a networking n00b and needed something simple. If I still had a pc running Win2k right now, then I probably wouldn't change it since it worked so well for what I needed. The hassle of a re-install is just not worth the benefits. But all of my new pc's will be XP Pro.