I have a Dell Latitude C840 and since last night it has been running at a speed of 1.2 GHz instead of the normal speed of 2.0 GHz. It's really annoying as everything's choppy as hell. I checked the BIOS and sometimes it says it runs at 2.0, and sometimes it runs at 1.2. The problem is I don't have the main password to permanently set it to 2.0 GHz (bought it used) and have no idea how to reset the password in order to change the clock speed. If there's another way of doing this without going through the BIOS, please let me know.