Which version of OSX can MacBookPro5,5 running 10.6.8 go to?

Upgrade to OS X El Capitan - Apple Support

Can your Mac use El Capitan?

OS X El Capitan requires one of the following Mac models and versions of OS X. It also requires at least 2GB of memory and 8.8GB of storage space.

• iMac (Mid 2007 or newer)
• MacBook (Late 2008 Aluminum, Early 2009, or newer)
• MacBook Pro (Mid 2007 or newer)
• MacBook Air (Late 2008 or newer)
• Mac mini (Early 2009 or newer)
• Mac Pro (Early 2008 or newer)
• Xserve (Early 2009)
• OS X Yosemite v10.10
• OS X Mavericks v10.9
• OS X Mountain Lion v10.8
• OS X Lion v10.7
• Mac OS X Snow Leopard v10.6.8

Corsair works just fine. My Late 2011 MBP is using the following since purchase with no issues. Even thru a logic board replacement under that model's repair program. Note it is Mac-specific, Mac-certified.

Dear Jim,

You may want your friend to do "About ths Mac" from her Apple menu (left end of menubar) and find out how much RAM is installed. Some older MBPs shipped with 2GB RAM, fine for Snow Leopard but "real-world short" for El Capitan. EC will run on 2GB but not as wellas it can. That model can be upgraded to as much as 8GB RAM and RAM is user-installable.

The caveat is that one can't use just any old bargain-basement RAM. I buy all my Mac RAM from Other World Computing:

https://eshop.macsales.com/shop/memory/Apple_MacBook_MacBook_Pro/Upgrade/DDR3

but also trust Crucial. Based on many reports around here, she wants to avoid PNY, Corsair, and Kingston's "ValueRAM."

Installation video for her model is here: Memory

If her computer already has 4GB RAM, I would recommend that she leave it there after getting EC until the computer shows a need for more. If she does not load up her computer with piles of third-party "useless-ware" like anti-virus and "cleaning/tune-up" apps she might be able to run that model on 4GB RAM for the rest of its service life.

Back up her data,check her applications for compatibility, click here, and download El Capitan from the Mac App Store.

(149444)