I have to upgrade to either Windows 2000 or Windows XP.  What are the
advantages of one over the other?
Here is a link to a good description of Windows XP, but I haven't
found as good a description of 2000, or a definitive
difference/comparison.
http://www.softwareoutlet.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=0464
On first blush, I would just assume that XP might be better just
because its newer, but I'm interested to hear if that's the whole
story, for example,"XP . . . activation to consider, a mildly annoying
anti-piracy measure that requires you to obtain a code from Microsoft
for full installation, and in the future if you reinstall or make
major system changes."  Does 2000 require this?
I am far from a computer handyman, so if 2000 is simpler or easier to
use, then that would be a great advantage for me.

As far as I am concerned and understand your requirements, you should
upgrade to Windows XP. Some parts of media made a huge hype of the
product activation and licensing measures. Not only is Windows XP is
newer it is a secure operating system by far. The end user experience
for Windows XP is very smooth as compared to Windows 2000 (which can
be described as scratchy at best). I have worked with with operating
systems right from DOS 3.12 and by far Windows XP is the best effort
yet (Though Vista looks very promising) from Microsoft.

As for the usability and user friendliness, Windows 2000 still retains
the quirks of Windows NT 4.0 (no extensive plug and play support,
difficult hardware driver installation, boxy look and feel to name a
few). Windows XP is fully plug and play compliant and very robust
operating system.

I would stonrgly recommend Windows XP over Windows 2000.

These search results might assist your decision:

"windows 2000 vs windows xp" OR "windows xp vs windows 2000" OR "2000
vs xp" OR "xp vs 2000"
://www.google.com/search?q=%22windows+2000+vs+windows+xp%22+OR+%22windows+xp+vs+windows+2000%22+OR+%222000+vs+xp%22+OR+%22xp+vs+2000%22

Going along with what thesolutioner-ga said, I too would strongly
recommend Windows XP over Windows 2000 for the simple fact that XP is
far more user friendly for the average user and just as secure as
Win2000 (particularly if you get XP Professional).  However, one
important factor to consider is your computer hardware.  If you've got
an older system, then Windows 2000 might still be the better option
because XP is, frankly speaking, a resource hog.  If you've got the
specs: Minimum 10GB hard drive space (more is always better), 512MB
memory (More is DEFINITELY always better), and 700MHz processor
(again.. faster is better - recommend 1GHz+), then XP should run
fairly well.. for basic home usage (word processing, surfing internet,
etc.  If you plan on playing computer games such as  Doom 3, Quake
2004+, FEAR, FarCry, Half Life 2 etc... then.. well.. the specs I just
listed just won't cut it for XP (let alone the gaming).

Hope this helps!

I would recommend XP Pro over 2000.
It boots faster, is pretty solid, stable and looks prettier too.
And ofcourse, a lot more user friendly than 2000.

Thesoutioner is incorrect.  Windows 2000 has the same plug and play
capabilities that Windows XP has, and the hardware driver installation
is the same.  "Under the hood" the two operating systems are mostly
identical.  The main differences are minor ones of user interface, and
a few added features of XP.  XP adds a few features such as CD
burning, and user switching (switching the user you're logged in as
without stopping all your running programs).  XP also comes with a
built in software firewall, so you could make an argument that it's
more secure, but if you're already behind a hardware firewall or a NAT
the difference is really quite minor.

Personally I've had much better luck with windows 2000 than XP, so the
minor advantages of XP over 2000 aren't worth the problems I've
exerienced.  The problems I've seen mostly seem to revolve around the
operating system becoming very slow to respond.  Your mileage may
vary.

I am a computer consultant here are a few more things I can add:

Reasons to go with XP:

1. Windows XP Pro has built in remote access based on terminal server
technology - which gives great performance.

2. Most of the latest processors like dual-core, hyper-threading
processors are properly supported by Windows XP, while may not be
fully utilized in Windows 2000 Pro

Reasons to go with 2000:

1. Runs much faster on older hardware - due to Windows 2000 lesser
overhead than XP, it will run faster on most hardware.  On older
hardware (say less than Pentium 4, 1.8Ghz) Windows 2000 will perform
much better.  On latest Pentium 4s (Hyper Threading/dual core) XP may
run faster than 2000.

as far as im concered go wiht xp from everything ive heard 200 was
pretty much a beta to xp tons of proboblems i had a machine that had
that on it and after i got imedatly i got xp go wiht xp pro to

One thing to consider is software support. Make sure the software you
acquire is supported. For example, Adobe Premiere Pro 1.5 only runs on
Windows XP.

XP: You'll like it alot if you want a streamlined user interface, and
backwards compatability with 99% of your old programs. As a plus, it
has a built-in software firewall if you want to use it. As a minus,
virtually all the specific-OS-targeting viruses out there are made for
XP. If you have a Hyper-Threaded processor, you need XP to unleash its
full abilities too.

Win2K: This system is rock-solid stable, and has alot fewer viruses
designed for it. Unfourtunately, it can't run some applications for
95/98/ME/XP. It's got the classic boxy user interface, too. If you
have a Hyper-Threaded processor, Win2K cannot fully utilize it -- in
fact, 2K can have REDUCED performance with HT processors.

Both: They both recognize hardware fairly well on their own.