I recently moved house and

That's fantastic, but other than blaming either Virgin or your new house for the PC problem, not terribly instructive.  What's this about a modem...you mean you connected your PC to Virgin's cablemodem using cat5 ethernet, which is pretty normal?

  Give exacting circumstances (e.g. timing after the BIOS and Windows screens came up) and descriptions of the error messages, and people can help out, especially if you go create a new problem under your exact PC model, and try to suss out the problem by googling for 'Port 00 error' and your model.  

As it is it sounds like Windows found bits of itself missing (as moving vans can cause sectors to go bad on HDs) and vainly hoped you would have the Windows 98 or XP install CD handy to fix things.  It is probably time to install a new hard drive and appropriate OS of your choice, and copy info over from the old drive before labeling and packing that thing for spare use.