One Copy of GW on two computers?

I have two pc's , and my gf wants to play GW at the same time. Do I have to buy another copy or does GW allow multiple copies as long as the IP is the same?

you'll have to buy a second game for her then.

You can have the client on more than one comp. I have it on three for one account. But for your girlfriend to play at the same time you do she would need her own activation code. If you just want her to have a character in your account to play when you are not playing one activation.

The good news is: just buy the applicable key code for the campaign you want and then copy your existing GW.dat file over to the PC that the new account will be played from.

This will save you time in getting a new install of Guild Wars setup by avoiding the updating and so forth.

Ok so I do need a new key , but she could play it on my second and her main pc at home , as long as she played at different times.

So long as you're both playing from 2 seperate accounts, you can both play at the same time, it's only if you're sharing an account with her (a big no no under the EULA) that only one of you could play at a time. ANet doesn't care if your overall IP is the same, just so long as you're each accessing a different account.

You can be as many people playing from the same place as long as you have 1 account for each person.

That is correct. Although I think it would be hard for her to be in two places at the same time anyway.