How do I tell how much memory I have on my desktop?

Right click the my computer Icon on the desktop or in the start menu. Then open the properties tab to view the system information window. Down at the bottom of the window it will tell you how much RAM you have.

Find out how much memory is in the computer by examining the BIOS or operating system. For Windows, this can be located by opening up the System properties from the Control Panel. Also open up the case while the computer is off and find the memory slots to determine how many modules are installed and how many slots are available. If all the slots are full, you may have to take some out to put more in, if the system can use larger modules

Check your operating system and application programs. Often they will have a printed "Minimum" and "Recommended" memory listing somewhere on the package or in the manual. Find the highest number out of "Recommended" section and try to plan on having this much or more memory by the time you are done upgrading your system memory.

Right click on My Computer and say Properties (or hit Start and Pause/Break - both do the same thing). Your memory will appear on the bottom right of the dialog box along with some other information.

I am assuming you have a Windows based computer here..you didnt say

RAM or Hard disk?

RAM.. your computer generally announces it during the boot up sequence.

Hard Disk: go to my computer and right click on the C drive. On the bottom of the menu select properties and it will give you the status of your hard disk (total/free/used).

See the example video here:

http://www.utipu.com/app/tip/id/535/

This video was created using the free screen recording application from http://www.utipu.com/

Goto

WWW.Crucial.com and let them scan your System that will tell you how much you have and What you can add

right click on "my computer" and go to properties.

start--->run--->dxdiag