can't remember password

Hardware MikroTik hardware general
1

no, you can only reset the password along with all other config:

http://wiki.mikrotik.com/wiki/MikroTik_Password_Recovery

2

you should reinstall with the CD then

3

License will not be touched if you only use MikroTik’s installer. Don’t use any other formating utilities

4

yes, exactly.

(you should not post in the routerboard forum, if you are using a PC)