Reuse RAM 205
I have a Dim4600, so you are probably using WinXP on it. You should have at least 512 MB of RAM on that PC. This is why Son1 is complaining about the gaming speed. If on the 4100 you are also using WinXP, again I would have at least 512 MB of RAM on that PC. That is just my own personal experience with WinXP on Dells.
Also you should install, and then run a spyware program such as Ad-Aware or SpyBot, on a regular basis, on your PC's.
Reuse RAM 206
The Dimension 4100 can accept up to 2 sticks of 256MB low-density PC133 168-pin SDRAM DIMMs. Doubling the memory would help. The Dimension...
Right now we have a Dell Dimension 4600 with 256MB RAM. The old one is a Dimension 4100, which has 128MB RAM.
Son1 complains about gaming. Someone mentioned the Video Card. Not sure what is in the 4600, the 4100 has 32MB NVIDA TNT2 M64 APG, whatever that is. Is there a way to check the card on the 4600 without opening it?