If you have a LabQuest 2 that was connected to a WPA2 Enterprise network where you enter a username/password, and either you mis-typed the username or you want to enter a different username than before, you will find that the username field in LabQuest is populated with the old username and grayed out (non-editable):

To edit the username:
1. Tap Cancel. This will take you back to the network selection screen with the network name and “failed” under it.
2. Tap the icon in the upper-right corner.
3. Tap the Forget Network button.
4. Re-select the network from the list; you will be prompted to enter a username again.