Changes made to your User Interface via Customization are saved in the user.mtx file found in the...
C:\Users\<username>\AppData\Local\Siemens\<NX version>
...folder. For versions prior to NX 9.0, this file is stored in the...
C:\Users\<username>\AppData\Local\Unigraphics Solutions\<NX version>
...folder. Note that you can at any time save a personal copy of these settings as a 'Role' which will be stored in a folder named 'roles' in the aforementioned folders.
As for the Customer Default settings, they will be stored in a file, again found in the aforementioned folders, which will start with the name of the NX version followed by '_user.dpv', such as 'NX90_user.dpv'. Also, if you've made any changes to any of the Drafting standards in Customer Defaults, there will be additional '_User.dpv' files for those settings as well.
To play it safe, just keep a back-up copy of the aforementioned folders as then you've basically have about 95% of all the settings which controls a session of NX, but keep in mind that if you continue to make changes to the UI or update Customer Defaults, that you will need to make sure that your back-up copy of this folder in as new as you think that you need it to be.
Now as for the other 5% of settings which effects a session of NX, there are the 'Preferences' settings and other system settings established at the time NX is installed, and these are saved in the Windows system registry. Now if you're an experienced admin then you will know how to keep back-up copies of your registries as well if you want those last few items copied.
Anyway, other then your actual working part files, these are the files that you need to back-up if your goal is to being able to fully recover your previous NX system settings.
John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Industry Sector
Cypress, CA
Siemens PLM:
UG/NX Museum:
To an Engineer, the glass is twice as big as it needs to be.