What does this have to do with XP? 🙄
Oh well, you could go into e-mail preferences and uncheck everything on each of the tabs and remove the mail account that you have it check.
Then you could go into the View/Change My Details and delete the e-mail address(es) from the Main section.
As far as deleting your icq mail account I guess you could e-mail them and ask them to delete it, otherwise just forget about it and they will probably delete it after some period of inactivity.
BTW, you could have just gone to the ICQ web site to find out how to do this🙂
