^ Thats if you can get that far....
If you can't then check if you can enter the BIOS, "Delete" button maybe. It should be shown on the motherboard screen as SETUP. If you can't enter it then you have a hardware problem. Also try reseting your CMOS after that...
[EDIT]
If you can open the boot menu as above said then ignore my instructions.
"you did on the laptop"
OP has clearly said that it is a desktop, Twice...