Notice: I do not know the router in question, the following is based on the test I just made with my
Belkin N1 Vision router.
I went to the router's control panel which is protected by password set by myself. I made a backup of router configuration settings and saved it.
After that, I reseted my router to factory defaults. This automatically meant that also the password to access router's control panel was reseted to default. I entered the default password to access router, and chose the option to restore previous settings.
Worked like a charm. The password of my router was reseted, and all the previous settings restored.
At least in my case, the router password is not stored in router configuration. It's just a local, browser password to enter the web interface.
Kari