Routers

[Archon_Wing]

Try to find the original CD-Key, and you could probably edit the registry or something(most games store their CD-Keys in the registry, not sure about D2) Actually, this is illegal, but you could also sneak into a cybercafe, steal the CD-Key from the registry, and change the number in the cybercafe's registry so that other people can't access B.Net from that particular computer. :P It's even more devious when you simply change ONE number and the tech people there will never figure out what's wrong(I've never actually done this before, but unscrupulous "friends" assure me it's possible)

Now that's plain wrong!
You can't steal the Cd-key from the registry easily anyways unless you use a program, and that's already suspicous enough. ;)

So, just reinstall the thing and contact tech support.