There are many programs that define the computer configuration and the types of component devices. Many of them are free. Download SiSoft Sandra and install it on your computer. Run the program. In the section "Information modules", find the icon "Summary" and click on it. After a while you will see the information window that provides information, including about the installed memory. Keep in mind that the free download is only available old versions of SiSoft Sandra.
The program CPU-Z to determine the configuration of the computer is free. After you install the analysis configuration. The result is displayed in the view window. Go to the Memory tab to see the type and characteristics of memory installed in your computer.
If for some reason you can't use the first two ways, disconnect the computer from the mains. Unscrew the tightening screws and remove the side panel. On the motherboard locate slot with the memory module is the smallest size external card. Pull down the plastic clips, which the module is mounted in the slot, remove it.
Currently, computers use three types of RAM: DDR SDRAM, DDR2 SDRAM, DD3 SDRAM. Memory type SDRAM it is gone buy the bar, most likely you will have to buy with it. Find the name of the manufacturer and the type of memory on the module.
If the memory is not marked, try to determine it yourself. Modules vary in the number of contacts:
- SDRAM – 168;

- DDR – 186;

- DDR2 – 240;

- DDR3 – 240.
And the location of the keys (the slots on the pad). This is because DDR, DDR2 and DDR3 are not compatible. Memory module DDR if it would be possible to insert it in the slot for DDR2 wouldn't work and Vice versa. On the strap 2 SDRAM slots.