If you'd like to sample Win8 in a Dual Boot, post back a screenshot of your maximized Disk Mgmt drive map and listings, using the Snipping Tool in Start menu - attach using paper clip in reply box. Dual Boot Installation - Windows 8 and Windows 7 or Vista - Windows 8 Forums
Otherwise save externally a Windows 7 backup image of your Windows 7 install so you have a path back: Backup Complete Computer - Create an Image Backup
I would also make your Factory Recovery disks since on most models Recovery will not run from its HD partition after the C drive is overwritten with a fresh or reinstall.
Most tech enthusiasts don't run the factory preinstalled Windows 7 but prefer to Clean Reinstall - Factory OEM Windows 7
- everything you need to do this is in the blue link. At the minimum with a factory install or recovery I'd Clean Up Factory Bloatware