Nothing to do with forum software, when you created the account you had the option to choose a user name (like most do) or use your e mail address (also like some do). You've now realised you chose the wrong option.
Note Mario and I are mods, we don't administer the forums so can't 'sort out' anything, let alone presto :)
I also understand, though I've never tried it, that if you log into opencaching.com that uses the same log in details as these forums, and you can change user name there.
I have asked that the ability to change user name should be on these forums too, but so far that has not been implemented.
Rubbish, I definitely have chosen a user name, it's just that the sw kicked it out as soon as i logged in with my email-address. The whole thing is reflecting the attitude Garmin shows towards the problems of users. The SW quality is a mess, just look at the topics of most posts here.
Go to the top of the this page and click on notifications, than inbox. Find "send new message" start typing in the Recipient Users box TRI.JANDS the name pops up, select it. Type in the title "Username change request" in the message give at least 2 new names u like to use.