Photos: How to upgrade your old PC to run Windows Vista and Windows 7
PC upgrade: Unplugging and preparation
Unplug the cards from your old PC and keep them in a safe place, because you'll reuse them on the new motherboard. Remove the back plate from the PC case and unscrew the old motherboard.
Cliff Saran provides a step-by-step guide to updating an ancient Pentium 4 3.2 GHz XP-based machine with 2 GBytes of memory to an AMD Phenom Quad Core PC with 4 Gbytes of memory running Windows Vista.
The hardware is built around a Gigabyte GA-MA790FX-DS5 motherboard.
NB: PC components can easily be damaged by static electricity - I recommend you use an anti-static wristband.