At the risk of sounding like a snob, computers do not slow down because
of wear, they slow down because of obsolescence. If you are saving
money to upgrade an 8 year old machine, you are far better off to save
for a little longer and buy a new machine. Even if a new machine is a
"bargain basement" model from your local box store, it is a quantum leap
over what can be done to an 8 year old machine. We are not talking
about that much of a difference in money being spent.

I would seriously install a XFCE environment into the Ubuntu on your old
machine and not upgrade it's hardware at all. Putting money into that
old of a machine is throwing good money after bad.

I'm technically just getting a new machine, minus what I already have
and don't need - I have a new PSU coming in, a new video card, I'm
looking at a new motherboard, a processor and RAM as well. I already
have one 30gb hard drive, a 160gb drive, a DVD drive, and a CD burner,
as well as a fairly good SoundBlaster. Figure there isn't a reason to
go out to buy a new system altogether when I'm just going to strip the
drives and most (if any) of the expansion cards and use what I have now
(in fact, the only thing that'll still be from the original system would
be the CD burner - everything else has already been replaced, or will be
replaced). My only question is while I wait a month or so to get it
all, I want to be able to utilize my current system as well as I can.

I would tell you that by the time you buy
all you plan the only thing you are not buying is an new tower and the
power pack. Firstly the new mother board may not fit in the older tower
and the power pack in it will be under powered, A new case is cheap with
at least a a power pack of at lease haf the power again and another
cable that powers your new mother board.

In your old system get rid of software you never use. The old
improvement is less junk and faster processing and more RAM.

I personally find that when it gets that old that any money invested
isnt really worth it in the long run.

I would suggest just getting a small form factor kit from newegg, a cpu,
ram and reuse your hd and for less than $500 you have a great system.

For less than $500.00, you can get a "bargain basement" system and still
have your old machine as a back up machine.

try using dsl(damn small linux) or puppy linux. i know dsl is 50 megs and will
run very quickly even on an old machine.

I'm finding the slowness a bit odd. My fastest box has a 333-MHz
clock. I've downloaded anything and everything I've had any curiosity
about. Excepting a couple KDE packages I downloaded by mistake, I've
left all that software on my HD. My 333-MHz box is still running
Ubuntu OK.

The PSU is already covered, as is the case - I know some people at a
community center that have a plethora of cases either empty or with
non-working motherboards, and they're willing to trade me a tower that
should support whatever board I buy, and seeing as this is a standard
ATX board, I don't see why that'd be a problem (this isn't the first
time I've switched the board out of a system) - even if I wanted to use
the same case, all I have to remove is the rear shield, and replace it
with the one that'll come with the new motherboard. Case I have is
already set for the ATX form factor - most of the reason I'm replacing
it is it gives the community center some working hardware without them
having to strip too much out of an existing system to put new stuff in
(and it means that I won't really have to change out boards, just throw
it in a new case and all that).

I think the word "Upgrade" might be misleading; I say it because most of
what I have NOW I'll be using. However, most of what I have NOW is not
part of the original system - none of the drives, save the CD Burner
are. Neither are any of the expansion cards, aside from the display
adapter, which, as I've already said, is going to be replaced. Pretty
much by the time I'm done getting the parts and all it'll be like having
built a system from scratch, since the only part that was originally in
the system when I got it, and will be moved to my new system will be the
CD burner. I honestly fail to see how not changing out a CD-RW drive is
the same as just adding a new part to the board and expecting it to be
faster. This isn't me adding some new adapters to the system and
expecting it to be faster; I'm not buying a processor for an obsolete
chipset and expecting blazing fast performance. I'm replacing
EVERYTHING - case, motherboard, processor and all. I ask the question
about what I should do because it'd be like taking the hard drive from
one system to another and expecting it to boot, and I want to know,
before I switch everything out, whether it'll be easier to try setting
up the system for the new hardware, or if I should go ahead and just
wipe the OS and start over.

I ask the question about upping my performance because I have to still
use my current hardware for another month or so, and, especially with
the idea that I'll have a faster computer soon, I'm getting a bit tired
about how slow my system is.

As to buying a bargain basement system, something that's $4-500 is not a
deal for me. At current I'm looking at less than $200 to get my system
in order and pretty much have a new system that'll last me for a good
long while (for example, I'm looking at a motherboard that's got both
PATA and SATA support, allowing me to use my current drives as well as
upgrade to SATA later on; it's using Intel's LGA775 chipset so I have a
nice wide range of processors to choose from if I want to upgrade from
the dual-core I'm getting). My feeling is that the prebuilt systems are
going to have hardware that I don't want or need, since I have enough
up-to-date hardware in my system at current to where I no longer have to
buy that much to have a good system.

If you install a bootable hard drive fron elsewhere all you need to do
is get the BIOS to read it and it should bot up OK.

A word of advice on the PSU. I just had to replace mine a short time
ago and I was unaware that motherboards have changed from 20-pin
connectors to 24-pin connectors. It took 3 trips to the store to get
a PSU that would actually support a 20-pin MB. If you are getting a
new MB, be sure to check that your PSU has a 24-pin connector.

BTW, I agree with your decision yo use as much of your old hardware as
possible. I can't see any reason for buying a pre-built computer if
you can handle a nut driver. If you do end up getting a new case, I
would recommend springing for one that has easy access to the drive
bays and the MB. The small towers can be a real PITA to work on
unless the drive bays pivot out of the way.