The tech was correct add more ram. To run XP decently, have at least 1gb installed. Depend on how you have your current ram installed, if 2x256mb modules or 4x128mb RDRAM for that 512mb total. The 8200, if I'm correct handles the most 1gb of ram, but the Dell support specs(or manual) will explain this. Now RDRAM is costly so do you really want to go this route? If yes, then find RDRAM via eBay or other online vendor and understand the retrun process if any. You will need to remove the "continuity modules(blank)) for full access to all ram slots, if not already, then remove lower ram modules to install higher ram modules if required. Also, this is done in "pairs".
I have a Dimension 8200 w/ Pentiuum 4 Processor at 2.0GHz, 512MB PC800 RDRAM running Windows XP SP3 that I purchased in April 2002. I is not as fast as it used to be (slowly getting slower). Two years ago I had to replace the hard drive, but it was still running slow. I defrag, run ccleaner, ad-aware, windows updates weekly; and have f-secure anti-virus on at all times. In addition I am on satellite internet which is always slow (almost as slow as dial-up, but that's my only other option here). Even working off line my system runs slow to the point where if I am working in windows it will lock up where one window will partially disappear into the other then finally move again. When on-line Outlook Express, when switching identities, will completely disappear, then pop back up as a different identity. I took it to my local computer tech fearing a virus, but was told no virus. The tech said more RAM may fix it, & that it's having trouble multitasking, then said it may be too old to put more money into. Other than the problem of being slow, this has been a good computer! Any suggestions of what I should do?