I try to install the MacBook Air SMC Update v1.9 but it says that my system is not compatible

Hi angelandres33,

The MacBook Air SMC update 1.9 is specifically for MacBook Air (mid 2012 and mid 2013) models, as noted in this page -

MacBook Air SMC Update v1.9

http://support.apple.com/kb/DL1627

Thanks for using Apple Support Communities.

Best,

Brett L

To check the model number hold down the option/alt key, go to the Apple menu and select System Information.

Should be 5.1 or 5.2.

I have had difficulty as well installing the Macbook Air SMC Update v1.9 on my MacAir 13'' mid-2012 model. I was hoping it might help with the intermittent shutdowns.