Can get in to my computer it say enter password dont know it

Look up a diagram for your motherboard to find out where the "clear cmos / clear password" switch is if you don't know. The contact will be over two of the three prongs. Move it to the other two and start the computer. The computer will not start, but once the power has been sent to the motherboard, it has done what you need. Unplug the computer and move the clip back onto the prongs it was on before. Plug back in and start the computer. When the cmos screen comes up; reset the time and date, save your settings and restart. If you are unfamiliar with how the cmos works; search "clearing the cmos / bios" on google or something. Good luck!