I think you are looking at a bootloader.
On the command line, run bcdedit.
You should have some options to change.
One might be to a delay of 0 seconds before booting from the default os.
everytime I start my PC windows 7 ask me where to boot from
It should be in the BIOS depending on what type of computer you have. Should be under boot settings. You just have to put your hard drive in the Boot number 1 Slot
I think you are looking at a bootloader.
On the command line, run bcdedit.
You should have some options to change.
One might be to a delay of 0 seconds before booting from the default os.