Upgrade or New?

Running a 2.0 Gig processor is more than adequate for what you want to do. I suspect that your performance problems may be due more to spyware infection than hardware problems.
If you havn't saved all those important files (shame on you if you have not) do so now. Then reformat this dude (no sense in trying to dig out all the spyware and resulting registry errors). Put in 1 Gig of RAM - can be bought cheap at Tigerdirect, etc.
As for USB 2.0 - you can get a PCI card with the new USB 2.0 slots fairly cheap.
$300 - $340 for 1 Gig of RAM?? Better check out the prices at Tigerdirect!!

In this case,if the processer is up to date, I would boost the ram to one gig, also you may have other issues that may cause your system to slow down, such as malware you may have picked up while web surfing or too many services or plug-ins running at the same time, also evaluate your internet connection.

This is a very good time to get a NEW PC but you Absolutely must be able to get though the Hype out there.
For that much money I hope Dell is giving you a 19" LCD and separate PCI-Express Card since pricing is in that range now. I'm just in the process of selling some systems just like that in AMD at $700 - $800 with LCDs too.
The other thing that makes all the difference is the Hard Drive since a lot of cheap drives will slow the system down more than anything else since it is the Last Link in the chain. Make sure it's a good brand and a Serial II 300gbs is a must even at the same price.
Finally there's Windows Vista that will be here in about a year and the Video should be compatable with it. Memory is so Overpriced now and it really makes little difference as long as the combination is a good one at 1gb.
I've built too many PC's to be guessing at this one and the Absolute most important thing to do is Reformat your drive with a clean OS install and sometimes you'll see a 50% speed increase.

Hey Aramine - I'll be real quick and simple here. Unless you have the need for a faster processor or you just want a new machine, your current system is just fine. Simply pull out and toss your 256MB RAM and purchase 2 1Gig sticks of RAM. Your old system will run like a new machine. Also, you may be running out of disk space soon so you may want to consider purchasing a second hard-drive, but that depends on whether you need it. I've alway found my system runs better with at least 30% free space.
Good luck.

I am trying to download a minor upgrade for iyunes and quicktime. It almost finishes when Iget an error saying something or smeone else is controlling my operating system. also get the same message using Windoctor. Help?

Buy new. in a yr, you will have spent over $500 to $600 dollars on upgrades and the computer will still be obsolete and you will need a new one. g for the new one now and it should last you for the next 5 years or better.

with the price of rambus it's hard to justify an upgrade unless you know someone else who has parked an old dell for the same reason. i have stockpiled some 800 and a gig of 1066 out of systems just like yours. i own a small PC shop so i am partial to someone shopping local instead of jumping on the phone and dialing dell. i offer components with a longer warranty than they do, a system with no proprietary parts so upgrades are easier/cheaper, the ability to hand pick each piece and i you need me i'm right down the street! unless you are buying one of their $399 specials, which i refuse to do because of quality and warranty issues, i can be very competitive on pricing!
dell has a great marketing strategy and it shows here in this thread. at least 50% of the people have told you to just call dell for a new system. now search for threads on the quality of service after the sale and i bet you find a lot of dell bashing over service. so it's up to to decide what is more important to you....quality and service or making the dell fans happy! and oh by the way, i'm quite sure, your current dell takes a "dell only" power supply too so you're stuck there as well!!