My build wont display when i turn it on! HELP :(

So i've just finished putting the parts of my build together. When i turn it on all the fans are whirring my disk drive works but i can't get my display on! :( I'm using the dvi port with a dvi -> hdmi cable.

Please help

Does the GPU fan turn on? Is the CPU power cable connected?

It's now working =P and i think it was something to do with the CPU power cable! thanks for your reply.

do i have to use a ps2 keybaord to navigate bios or is usb fine?

USB is fine.

A new issue has arisen! When installing my OS it asks me to install my harddrives drivers. Its detecting it fine but wont let me progress! :( This is a nightmare haha. I dont have any drivers for it i bought it second hand. It say no signed drivers were found. 

It's on! This message has been typed from my new rig! WOOOP WELCOME TO PC GAMING! :P