Registering Your BSAs
For OpenMW users, instead see how to edit your OpenMW config file.
To register your BSA files, open up your Morrowind.ini, which is found in the Morrowind folder. If you do not see Morrowind.ini, run MorrowindLauncher.exe and open up the options menu to generate a new ini.
Backup your ini before you make any changes to it.
Down the bottom of the ini file you will see a list under "[Archives]". Add in TR_Data.bsa and PT_Data.bsa if it they are not already listed by copying and pasting the section below. Save the file and exit it.
Your Morrowind.ini should be in your Morrowind folder. Scroll down to the bottom to see the archive list.
Make sure you have PT_Data and TR_Data listed. They should be after BM & TB.
Also, make sure your Game Files list is at the VERY bottom of the ini file. Otherwise weird issues can happen.
Cut and paste it to move it to the very bottom if needed.
And now, your copy of Tamriel Rebuilt should be ready to play! For any further troubleshooting, see the complete installation guide.