Fraz,
You say that you still had the problems AFTER reinstalling Windows?
Winsock32 is a pretty fundamental part of WIndows Networking and without it you're not going to be able to to a great deal!
A complete reinstall of the Windows TCP/IP stack looks like it's needed, but that's relatively easy. Just remove all components shown in Control Panel > Network and also your modem (from Control Panel > Modems).
If you then restart your PC, reinstall the modem driver, you should find that your essential networking components have magically reappeared.
Try and download (eg) Yahoo free dialup software from your work PC, bang it on a disk and install from home. If you've done it right, it should easily detect your modem and, if required, TCP/IP and friends.
I normally keep a couple of spare Internet providers' dialups on my PC just in case I can't get onto my main one.
Let us know if that worked.
Winsock32 can be overwritten by some viruses so make sure you've got up-to-date virus protection on your machine.
It's unlikely to be the fault of your ISP that your box can't find Winsock (unless they're shipping dodgy installation CD's!).
Hope something here helps...
GE