Sorry for the slight delay; I had to get one of my 600 systems out of the closet; it's about the same age as your 770 and I think it should act the same for this exercise. Yes, if there's a Supervisor password set, hitting just the Enter key at the lock prompt will display an OK message. When this is done immediately after replacing the CMOS battery, you should also get an error screen with codes 161 and 163, using the same graphical icons and colors as Easy Setup. Clicking on the OK button will show another error screen which again lists 161 and 163 and a suggestion to consult the manual. You won't be able to do anything except turn off the system. You must enter the correct Supervisor password at the prompt in order to obtain access to Easy Setup where you have to reset the date and time. Doing so will clear the 161 and 163 errors and finally allow you to boot an operating system.
If you are sure that you have never entered a Supervisor password and you have never previously attempted to access the Easy Setup menu, then did you purchase the system used? If so, the previous owner may have put one in the system and never told you. It is against forum rules to publicly discuss any method of bypassing Thinkpad security systems so the only suggestions I have at the moment follows:
- remove the CMOS battery for 10-15 seconds and replace it
- follow the procedure to remove a Power On password from the Hardware Maintenance Manual: http://support.lenovo.com/en_US/product ... FAN-3TSMGJ
(Pages 25 and 116)