To find your characters user data file follow the path:

My Documents (a)/EA Games (b)/UO Stygian Abyss (c)/User Data (d)/Account Name (e)/Shard Name (f)

(a) My Documents: all data files for your characters are located within folders in this directory
(b) EA Games: contains data files for each client
(c) UO Stygian Abyss: holds the data file folder for this client and the folder for all screenshots taken with the default <printscreen> hotkey.
(d) User Data: Holds folders for EA_ Context Menu, UO_Chatwindow and folders for each Account you have by account name. This folder also contains your global UserSettings.xml file and your Waypoints.xml file.
(e) Account Name:  Select which accounts files you wish to view, all shards will be displayed where you have created characters on that account.
(f) Shard Name: select the shard of the characters on the above account you wish to view, ie Atlantic, Oceania etc. The characters on that shard will appear to the right (g).
(g) The character files.

It is handy to know where your user data and character files are stored for a number of reasons:

If you wish to ‘experiment’ with your hotbars, desktop settings, assigned keys etc but you want to make sure you don’t ‘mess’ up what you already have you can highlight the character file you intend to alter and copy the file to a different place on your harddrive. In the event that you really don’t like your changes, you can then copy your ‘saved’ file back to the folder and it will put all you had back as it was.

If you always make sure that you keep a copy of your character files once you are ‘happy’ with their set up and macros/hotbars etc, in another location, in the event you need to uninstall the client and reinstall you can copy them back in and not lose all the work you did setting them up.

If you travel and intend to ‘play’ UO on another machine, you can email yourself your character files, when you get where you are going and log in to the game to establish an account and shard folder with a character file (automatic on log in) you can then copy all your ‘set up’ character files into the shard folder on the new PC and be good to go. This also works if you upgrade your PC so that after installation you are not starting from scratch.

If for whatever reason one of your character files becomes ‘corrupt’ in anyway you can just ‘delete’ the character file concerned, to remove all user data stored on that character. Logging back into the game after deletion will give you a clean slate. Deleting these files does NOT delete your character just it’s desktop settings, your ‘actual’ characters are stored by EA and will always be there!

If you are familiar with editing, you may copy macros created on one character to another, in fact if you have a particular ‘screen layout’ with all the default settings you have set up for game play, you may copy the ‘whole’ character file to all your characters prior to customizing those characters. This may also include any generic macros that you would like across all characters in your account. You may even share your screen layout as a .txt file for others to ‘copy’ and ‘paste’ to their own characters files. This is done by saving the file over an existing character file by ‘saving as’ and clicking the character you wish to have the new desktop or just renaming the file to a new character name and pasting to the folder.