To enter the BIOS menu you can use hot keys or key combinations. Hot key depends on the type of device used, usually it is Delete, F2 or Escape. There are cases where these combinations do not work or work, but the menu is not fully loaded. In this case, you must diagnose the problem.
First you need to check the keyboard and mouse standards. Some models of motherboards does not perceive properly the keyboard with a usb plug. Why can it happen? The problem lies in devices that are connected to the Board. An example is the use of the usb3 interface and connected card reader.
The ongoing conflict be resolved quite simply: to connect a keyboard with ps/2 interface or disable built-in system unit card reader. There's no other way, is to sacrifice one.
In some cases, may be guilty of the monitor. For example, when buying a computer your system unit was tested and was serviceable, but at home the same actions cannot be performed. If you discard the version with the keyboard, look to the configuration of the monitor.
Most likely, at the initial inspection of the computer in the system BIOS recorded the original resolution of the screen and on the "home" monitor that has no function "AutoConfig", it was already different. Thus, the solution to this problem is obvious: hook up a monitor to decrease the screen resolution.
It often happens that the only solution would be to update the BIOS firmware. This operation is easy, but requires care. Be very careful when choosing this option. Don't forget to make a backup before flashing.