How to tell how much ram an old PC can take?

[i dont want a username]

Hello.
My friends sister has an old PC which she believes to be at least 6 years old. She thinks it is a dell but says it is too slow for her to use most of the time. I said that i could possibly put some more ram in it for her.
The only thing is that I don't know how to tell how much ram can be put in an old motherboard or what type it uses and I assume that they have no longer got the manual.
Could someone please direct me on how to work out what ram can be put in an old motherboard or if there are any other low cost ways to improve the speed of her computer.

Thanks in advance.

 

[rolli59]

If ram helps at all then information from the manufacturer is usually available on the internet if you know the make and model number!

 

[Dereck47]

Download CPU-Z software from cpuid.com. After you run software click on the "Mainboard" tab. It will show you the manufacturer and model of the motheboard.

With that information you can go to the manufacturer's website to see how much and what type of ram can be installed.