How to re-install Yosemite when recovery partition is mavericks?

[whitedragon101]

2011 17" Macbook Pro

I am trying to re-install Yosemite because Trim enabler is stopping the system booting (tried the fix at https://www.cindori.org/trim-enabler-and-yosemite/ didn't work).

It says the last option is to re-install OS X from the recovery partition which will leave programs and data intact but install a new copy of the OS.

However when I boot into recovery partition to re-install OSX it says Mavericks not Yosemite. How do I do a re-install of Yosemite ? If I download the Yosemite installer to an external drive can I re-install over the top from there, leaving data and apps intact?

 

[whitedragon101]

Just done it. Turns out you can install from a normal Yosemite USB installer right over the top of the old OS leaving everything intact. Awesome. (Wish windows could do this. Would solve a lot of problems there too)

 

[z31fanatic]

Wish windows could do this. Would solve a lot of problems there too

I don't know about Windows on a Mac but on a PC, you can install a newer Windows OS on top of the old one and not lose anything. You choose the upgrade option.