You should be able to copy the init.m file from the "good" computer to the "bad" one. To find where the file lives, evaluate
Then go to that directory and open the folder called FrontEnd, where you should find the init.m file that you need. (There is also an init.m file in the Kernel folder in your $UserBaseDirectory, but it is the one in FrontEnd that you need).
On 6/15/2013 4:15 AM, Themis Matsoukas wrote: > When I installed v9 I kept the default notebook style from v8. I > updated to v9.0.1 and things were just fine until all of a sudden, > mathematica reset all my preferences: now old and new notebooks open in > the new v9 Default, and all of my customizations in the notebook window > (rulers, etc) are gone. On a different computer things still work > correctly. Can I move com.wolfram.Mathematica.plist.lockfile or some > other file from the "good" computer to the "bad" to restore my previous > settings?