My computer absolutely rejects DVD-ROM drives!

A few months ago, my computer–a Dell Inspiron Desktop which I bought last year–no longer accepts its built-in DVD-ROM drive. (The computer uses Windows 7.) I called a technician sent out by the store where I bought it, but he could not fix it; no other external disk drive–new or old–will work in it. I get a message accompanying the icon in Properties under Control Panel; ‘Windows cannot locate the drive for this device; the driver is either corrupted or missing. Code 39.’
The technician suggested that the operating system (Windows 7) may be bad, which means I have to get a new Windows 7 disk (I do NOT want Windows 8) and reload all the data on the hard drive from backup sources. Is he right? Or what?

The store you bought it from should offer recovery discs. Failing that you can create a system repair disc.

But before you do that, I would run this fix. Just scroll down to the resolution section and click ‘run now’ if you don’t feel comfortable following the instructions to fix it yourself.
There’s also some troubleshooting tips here. It’s hard to say, without actually physically going through them on your PC what might be the problem. But hopefully that gives you something to work with before you go reinstalling the OS!