There's dimension 2400, 4600, 4600C and so on.  What is the difference between them, I really don't know what dimension means.  First I was thinking about a 4600, but then I thought maybe a 4600C because it looked smaller and cooler.  Are there any major differences?  What's the adantage to getting a 4600 over a 4600C or vise-versa?

I assume you are talking about Dell's. Usually the higher the number with Dell, the more standard features it has on it.

The 2400 is pretty basic and is only good for cruising the internet, email, and basic programs. The 4600 and 4600compact ones have fancier motherboards which allow for more options like graphic cards and such. If you get a few upgrades on the 4600, you can play DVD's and higher end video games relatively well.

If you are a serious gamer or like your DVD's to be top notch, go for the 8400 with some video/sound card upgrades. If you are hardcore and want the badest PC on the block, get the XPS.

Hope that helps.

If I recall correctly, the 4600C is not upgradeable as far as RAM, etc.; that is the difference in it and the 4600.

I've got the 4600. Great machine. The 2400 has the graphics built into the motherboard while the 4600 has a separate graphics card. Good to remember if you ever want to upgrade the graphics.
The 4600 is a middle of the road machine. The 8400 is higher end for gamers, etc.  Check out techbargains for daily sales on Dell computers.

www.techbargains.com

You would be better off going with the 4600.  The 4600c would only be usefull if space is limited.  However, you would be much better off having someone build you a workstation that would fit your needs.  for the 700 that they are asking for the basic 4600 you could build one heck of a performance system.