Windows 7 randomly broke, won't fix!

After being forced to hold the power button for 4 seconds (because of Windows 7 freezing again), I turned it on today when I got home and normally when I have to shut it off like that it puts me into the "Windows did not shut down properly" page, where you can go into safe mode or start normally--but it skips that and requires the Windows 7 installation DVD.

That was annoying/confusing enough, but I threw it in and it loaded the installation page where I cannot do anything. When I try to install (even though it's already installed) it says "take out disc, restart computer and put the disc in when prompted" (which is when it says "system boot failure, enter disc and press enter").

So it won't install, and it cannot restore for some reason, and it does not have Windows 7 as a listed option in Repair, and when I do the other repair thing it does not find any problems and every single thing I do puts me back into the same loop of "Please restart your computer that costed a ton of money and hope Windows 7 works this time!"

Setup has nothing to help, so that's out of the question. Does anybody know what to do? I have literally no clue. Is there a complete wipe-of-everything-button inside computers that I can push? Because Windows will not reinstall and there is no uninstall option.

Boot into bios and check your boot priority order. Set your hdd as the first boot device. To get into bios, restart computer, then press F2 or Del key (depends on the system).