"You might think that modern PCs have more than enough memory. Even budget systems come with at least 2GB, and you can add 2GB more from as little as £20. 4GB of RAM should be enough for everyone, right?
Well, maybe not. Windows Vista needs 2GB to run properly, and large apps can swallow up a gigabyte more with ease. You can very quickly find that your 2GB system is grinding to a halt. Installing another 2GB may not make much difference. Very few 32-bit systems are able to access the full 4GB of memory – some can use less than 3GB. And upgrading to 64-bit Windows doesn't always help."