I assume you are referring to a system (hardware) password that you are challenged for when powering up the laptop, not the operating system password. You can just reinstalll the O/S into another folder to get access to the system and all the data files ...
Two types of system passwords exist;
1 type is the password stored in an area of the mainboard that is called CMOS (Complementary Metal-Oxide Semiconductor) a completely fancy way of saying an area whoes data is kept alive by a battery. You need to know if your model laptop uses a CMOS battery and how you can disconnect it. Go to the manufactures website at: http://www.medion.co.uk/
. If you can pull the battery for 30 minutes or so, then you may erase the password.
2 If you have a system that writes this password to a non-destructive area of the systems memeory in order to prevent data theft, you have a more difficult time removing the password. Some Lenovo systems must swap out the main board. the password cannot be accessed. Try the battery if you can, else Google medion laptop hacks