How can I determine the amount of memory allowed in my PC?

I have a Dell PC and have been told that depending on the type of motherboard, I may be limited in what size of memory will work.

The PC is around 5-6 years old and has Rambus memory. Of the 4 slots 2 are 125 and the other two are blanks. I would like to fill all 4 with 250's going to 1 GB. Is that possible? Is there somewhere on the PC I can figure this out?

The reason I'm looking into this is the PC continually freezes for 5, 10, 15 minutes before I can complete the next task. I have defragged it, compresssed files, run anti Adware scans, numerous Norton scans for viruses and have none, so I'm guessing that memory must be the problem. If there are any other ideas, I'm open for suggestions.

How can I determine the amount of memory allowed in my PC?computer virus

I recommend a free scan of the computer at Crucial. Not only will say how much and what type of memory (RAM) the computer has installed, it will tell you how much more and of what type can be add per slot.

http://www.crucial.com/

http://www.crucial.com/uk

wdw

How can I determine the amount of memory allowed in my PC?free spyware remover

I always use kingston.com you can input the type of PC and it will tell you everything you need to know
Go here: http://www.crucial.com

If you're running a 32-bit operating system, you will only be able to address 32-bits of memory at a time. Multiply that out and you get 4GB, but when you take into consideration the memory reserved for video RAM and bios space, you won't be able to hit all 4GB.

Point being? Get 3GB and you should do fine. Either that, or get a 64-bit operating system.
go to www.4allmemory.com
You need to find out what motherboard you have and that will tell you how much memory you can have.
You can try http://18004memory.com/ and click check my computer. It will tell you how much you currently have an how much you can install. In addition, It will also tell you what type of memory to purchase.