Help! I forgot my password, how can I change screen resolution...?

Right now, I can only log into guest account on this computer (Dell Dimension B110, desktop)



Nobody knows the administrator password. When I log into guest account, the internet doesn't work, it's like it's disabled.



However, if I press F8 when the computer is restarting, and go to SAFE MODE WITH NETWORKING, the internet does work, but the resolution is really big and control panel won't let me change it.



What can I do?Help! I forgot my password, how can I change screen resolution...?
you cannot change the screen resolution in safe mode, when logging into safe mode log into the admin account, then go to user accounts in the control panel and there you can change the password in the main user account by clicking on that account and select change password, then enter a simple password such as abcd and save it, then restart the pc and you will be able to log into the main user account with the new password