Quite an important question!

Thompers

Ascalonian Squire

Join Date: Feb 2007

meat n cheese

Me/N

If i have a username can i download guildwars, factions, or nightfall or and play them on that username

EntityMaster

Ascalonian Squire

Join Date: Jul 2006

If you have a user name and password and the corresponding account has stored valid CD-keys for those campaigns, yes you may just download the client from GW website and play via entering that account information.