|From the sounds of it, I'd guess your NIC (network interface) is toast. I'm guessing you've rebooted a few times since it first disappeared and if windows doesn't "find" the new device on bootup, it's a safe bet it's gone.|
I'd recommend taking your laptop to a reputable computer store and either have them diagnose your problem (and likely confirm what I've said) or just buy a new NIC for your laptop. You should have two PCMCIA slots on the laptop and if so, you could put a NIC in one of them.
If you do take it in to have it diagnosed, you shouldn't have to pay for more than 30 min's of labor as it should not take more than about 20 min's to diagnose the issue with the onboard NIC. Also, pay attention to the fact I said "reputable computer store" and not "electronics store" If you take it somewhere like future shop, it's more likely the person looking at your laptop is well, less in the know, than the person doing the same job at a real computer store (ie: a store that sells computers and computer peripherals and nothing else).
That's not to say you can't shop around for a new NIC wherever you want to. I would. But I wouldn't take my computer to an electronics store to have it looked at.
It matters not how straight the gate,
How charged with punishments the scroll,
I am the master of my fate;
I am the captain of my soul.