Thinking of buying a top-of-the-range Windows Vista PC with loads of RAM? Then just be sure that "loads" is no more than 3GB: you could be throwing away anything from £50 upwards.

Buy a PC with 4GB of RAM, and you can wave goodbye the last gigabyte. The reason is the memory-mapped input-output (MMIO) method - the system by which PCs communicate with installed devices, such as graphics cards.