ok this isn't much of a hack. but if you are into dat file editing, and you get really tired of changing the dat files back after every update! i can cut your time down to seconds. it just takes alot of work to write it up
If you like to have several dat files edited like for me i prefer to have my avatars all big, my icons changed, font changed and windows changed. etc etc. you CAN back up your FFXI info onto a back up harddrive *good idea anyway if you don't wish to download 14000 files when you reinstall*But if you have the Hard drive space.. then copy FFXI folder somewhere else. you can then open up your Notepad
START>>PROGRAMS>>ACCESSORIES>>NOTEPAD.exe
Here is is example of a batchfile which is typed into Notepad. and this line is pretty much the same everytime when you make the batchfile just have to change the locations of where you have the installed FFXI folders.:
(!empty($user->lang['CODE'])) ? $user->lang['CODE'] : ucwords(strtolower(str_replace('_', ' ', 'CODE'))):
COPY "E:\FINAL FANTASY XI\ROM\119\58.DAT" "C:\Program Files\PlayOnline\SquareEnix\FINAL FANTASY XI\ROM\97\68.dat" /Y
----NEW LINE----
COPY "E:\FINAL FANTASY XI\ROM\14\79.DAT" "C:\Program Files\PlayOnline\SquareEnix\FINAL FANTASY XI\ROM\113\68.dat" /Y
----NEW LINE----
ETC, ETC, Rinse and repeat.
-COPY - Means you are copying one file to the other
-E:\ - In this example is my backup of FFXI
-C:\ - Is where you desire to copy to.
-/Y - this means yes you wish to replace a file w/o a prompt to do so.
Then when you are finished save it as something like "FFXIdatrep.BAT"
.BAT at the end is important
now sometimes, depending on if you change alot. it can take a little time to write... but once you have it done it takes 5 seconds or so to replace everything. very very convenient.