My mid 2009 MacBook Pro will no longer recognize DVD's.

Hi there joe.l,

If I understand correctly your computers DVD/CD drive isn't seeing your install disc to boot from. If it is also not recognized in the OS when you boot, I would recommend the following section of this article to help you out here:

Get help with the slot-loading SuperDrive on your Mac computer

Accepts discs but they don't mount or are automatically ejected

1. Make sure the drive is not placed upside down. The aluminum enclosure should be facing up as shown in section 1.
2. Check the disc's surface for scratches and dirt, since these things can prevent the disc from appearing on the desktop.
3. Connect the MacBook Air SuperDrive directly to the computer's USB port instead a USB hub.
4. Reset the System Management Controller (SMC).
5. Ensure your drive can read the specific type of disc being used. The System Profiler or System Information may provide additional information regarding what media your computer supports.
   • OS X Snow Leopard v10.6 or earlier: Open Apple System Profiler by choosing "About this Mac" from the Apple () menu. Then, click More Info.
   • OS X Lion v10.7 and later: Click the Apple () menu and then hold down the Option key. Choose System Information from the menu.
6. If the disc continues to not be recognized, contact Apple or an Apple Authorized Service Provider, or make an appointment with an Apple Retail Store.

Thank you for using Apple Support Communities.

Regards,

Sterling

Also have a 2009 Macbook Pro, now upgraded to the Yosemite OS. Factory-installed SuperDrive accepted but failed to read (and ejected) both a software CD (TurboTax) and a movie DVD. My System Profiler says it will read DVDs. Any chance it has something to do with the new OS?