While the benefits of formatting a computer are usually the priority, the sudden realisation that the entire VALVe game line-up needs to be re-updated on a 33k should get you REALLY depressed quite quickly.
Yes, thanks to some extremly dodgy keyboard drivers, I've had to format my computer, which meant deleting the long hours spent updating HL2, CS:S and HL2DM. At the moment, I'm reinstalling HL2 from the original retail CD's. There's a long, hard struggle ahead folks...