Making Windows run faster: upgrade your PC

Mo' Memory
One of the major causes of windows running slowly is a lack of physical memory (called RAM). When this physical memory becomes full, Windows shuffles the information used by inactive programs into a file on your hard-drive called a 'page file' (or sometimes a 'swap file'). This shuffling back and forth of information takes time and slows the operation of your PC down.

Buying and installing more RAM is one way to give your PC a speed boost. There are many different types of RAM available, and you have to install the one that is correct for your PC. You can use the Crucial Memory Advisor™ tool to find out what types of memory your PC supports (Crucial are a major supplier of memory with prices often cheaper than you will find elsewhere). If you need advice about installing your new RAM, check out the How to install RAM article at lifehacker.

Veni Video Vici
Many computers these days have video controller built onto the motherboard (the motherboard is the big circuit board in your PC that all the other devices connect to). If you have such a system, the PC will allocate part of the available RAM to your video hardware, thus making it unavailable for Windows. Also, some software - especially games - relies on a sizable amount of video memory being available. So, another way to give your PC a speed boost is to upgrade the video card. Check out Ryan Pollack's article How to Upgrade and Install a Video Card?

If you have inbuilt video hardware on your motherboard you may have to switch it off in the BIOS (this controls the hardware of your PC before Windows starts), in order to do this consult your manuals. Note: if you have lost the manual you may be able to download it from your PC manufacturer's website.

Pimp my PC
Of course the best upgrade to make your PC run faster is to replace the processor (also known as CPU) with a faster one. The CPU is analogous to the engine in a car, so the powerful it is, the faster the PC will run. Replacing the CPU is not a simple task and should be avoided by computer novices. Your PC may not support all processor types and the actual task of replacing a CPU can be rather fiddly. For this, it would be best to seek the advice of an expert.

Note for laptop users
Of these three upgrades, only the first really applies to you. Changing graphics and CPUs on laptops would either be impossible or expensive. From personal experience I warn you to never take your laptop apart, the manufacturers really jam everything in there, and the whole thing becomes some sort of fiendish puzzle.