What can I do to NOT lose my password?
Don't use one
The easiest way to avoid losing your password is to not use one in the first place. The password protection feature is very low quality, and provides only minimal security anyway. Setting a password on your RPG file is like locking your door with a strip of duct-tape and a post-it note that says:
If you Insist
If your faith in "The honor system" is so small that you really want to apply that strip of duct-tape anyway, there are a few things you can do to make sure you don't accadentally lock yourself out of your own game
Only Lock the Release Copy
While you are working on your game, leave the game without any password. When you are ready to release your game, make a copy of it, and add a password only to the copy. If you forget your password, at least you still have the copy
Use a Password You can Remember
Choose a password you are unlikely to forget. You probably won't have trouble remembering your grandmother's name, or the name of your first pet, or your little sister's birth-date. Security experts will tell you that easy-to-remember passwords are bad because they are easy for other people who know you well to guess-- but if these same security experts saw the way passwords are implemented in the OHRRPGCE, they would probably have heart-attacks, so don't worry about it.
Write It Down
Post-it-notes are your friends. Write you password down, and then stick it to the corner of your monitor. If you are worried about friends coming into your room, reading your password and hax0ring your game, then hide the paper somewhere.
Email It To Yourself
Just send yourself a simple email saying "My OHR password is *****". This way, you can look it up from any computer with internet access. This assumes you will not forget your email account's password. Variants on this scheme include password-protecting a ZIPped text file or an MSWord file.