Windows 7: Missing Operating System after bad HDD driver install

Hi everybody...I have a Dell Inspiron15r model N5010 that I was trying to upgrade to windows 8 Pro when I went and downloaded many of the drivers from Dell so that I had all the latest and greatest. in my quest for quickness, I accidentally installed a driver for a HD that was listed when I meant to install the newest drivers for the accelerated HD graphics card. as soon as I did, the computer restarted and the infamous "missing operating system" message appeared. I checked the BIOS to see if the HD was still listed, and it is. I took the laptop all the way down to bones and removed CMOS to see if this would reset all drivers to loaded defaults, and this didn't work either. Please help.

This is not XP. Windows 7 is the first driver-complete OS in the installer, quickly updated via optional Windows Update after enabling Automatically get recommended drivers and updates for your hardware.

Only after all Updates are done should you import any drivers still missing in Device Manager from Support Downloads webpage for your tag number.

What I would do is follow these steps to assure a perfect Clean Reinstall - Factory OEM Windows 7 paying close attention to how drivers are handled, and the tools and methods which work best for Windows 7.

If you want to try to undo what you've already done, then boot installer into Repair console on second screen and run Startup Repair. If it doesn't offer it, run System Restore from the System Recovery Options list.

gregrocker....thank you, I went through all your materials linked and found the problem. the clean install of windows 7 not only fixed the missing operating system problem, it solved the windows 8 upgrade. I am now writing this from the computer that was affected, and it has never been faster, so much more so that I have a copy of all the materials you posted within your post because it is now my BIBLE. thank you, and this issue is definitely SOLVED.

Good work, Tommy!

Thanks for the kind comments and you are most welcome!