I advise you to make a copy of your registry before attempting this change. This can be done from the "boot to dos" setting from shutdown or from f8 on initial boot. Run scanreg /backup.
Now that the registry is backed up, run regedit from normal boot. Go to> Hot Key Local Machine> software>microsoft>windows>current version>policies>ratings...Delete key on right side of screen. Nothing left but default. Go to the registry tab at top and select exit to make changes.
Now you will be able to go into Ie> content and there will be no password. There is also a hidden file in the windows directory < maybe windows/system> with the pol extension...maybe ratings.pol? that can be deleted after the registry changes have been made. In any case if youdo the first part you have access to content.
Regards,
Bo