Computer Hardware:
     • Tools, Static & Cleaning
     • Form Factor
     • PC Case & Fans
     • Motherboard
     • Processor (CPU)
     • Power Supply Unit
     • RAM
     • Hard Drive
     • Solid State Drive
     • Optical Drive
     • Floppy Disk Drive
     • Graphics Card
     • Sound Card
     • Network Card
     • Computer Monitor
     • Keyboard & Mouse
     • Laptop / Netbook
     • Building a Computer
     • Overclocking

Operating System & Backup:
     • Operating System
     • Drivers
     • Windows Tools
     • User Accounts
     • Backup
     • Windows 10

Internet & Network:
     • Internet
     • Wi-fi or Cable
     • Improve Broadband Speed
     • Network Computers

Computer Peripherals:
     • Printer
     • Scanner
     • External Hard Drive
     • USB Flash Drive

Computer Security:
     • Anti-virus
     • Anti-Spyware
     • Phishing
     • Firewall

Common PC Problems:
     • Slow Computer
     • Hardware Failure
     • Software Failure
     • Printing Problems

     • Windows Shortcuts
     • Glossary of Terms
     • HTML Colour Picker
     • Number Base Converter


The main system memory of a computer is called RAM (Random Access Memory). RAM is temporary storage for the computer to run the operating system and other programs. As RAM is volatile it will only retain data while the computer is switched on. The RAM on a computer is found on memory modules.

RAM - SO-DIMM DDR (Laptop) & SDRAM (Desktop) memory modules
RAM - SO-DIMM DDR (Laptop) & SDRAM (Desktop).

If your computer has an insufficient amount of RAM then you will find that it will be very slow as it is forced to use virtual memory by accessing your hard drive. Adding more RAM will make your computer faster and smoother while it allows you to open more applications at once and will cope better with large files and video editing etc.

There are different types of Desktop computer RAM such as SDRAM (Synchronous Dynamic Random Access Memory), DDR SDRAM (Double Data Rate SDRAM), DDR2 SDRAM, DDR3 SDRAM, and now DDR4 SDRAM. Despite these memory modules being physically the same size, they are not compatible with each other. Each of these memory modules has a notch in the contacts which is placed in different positions so that it is impossible to match the wrong type of RAM with the motherboard's memory slots. The memory modules are also called DIMMs (Dual In-line Memory Modules).

Memory Modules installed in Motherboard

Memory Modules installed in Motherboard.

You may also come across some of the more recent memory modules that have a cover called a heat-spreader which is designed to keep the RAM cool.

Replacing RAM is one of the few upgrades that you can perform on a laptop. You will notice that laptop memory modules are physically smaller than the equivalent desktop computer memory. Laptop memory modules are also called SO-DIMM (Small Outline Dual in-line Memory Module). See Laptop page.

How do i know how much RAM i have and what type it is?

If you are using a Windows operating system then click START, then right-click on COMPUTER and select the SYSTEM PROPERTIES tab. This will tell you how much installed RAM you have. To find out which type of RAM it is then you can either check your motherboard manual or look inside the computer at the sticker on your existing memory modules.

An easier way to find out this information is to visit the Crucial website at: and run their system scanner which will scan your computer and tell you the type of RAM, amount of RAM, number of memory slots on your motherboard, and the maximum amount of memory that you can install in your computer. It will also give you the price of replacement memory modules.

Some motherboards support Dual-channel memory and you will see that the memory slots on the motherboard are colour coded. It is recommended that you match each coloured memory slot with the same type of memory module.

You should be aware that if you are using a 32-bit operating system then you will only be able to use up to 4GB (actually about 3.25GB of useable memory) of RAM regardless of how much more you have installed. If you intend to install more than 4GB of RAM then you need to be using a 64-bit operating system.