I Lost my MAC OS X yosmite

Hi Everyone,
Yesterday i have lost my Mac OS when i try to partition the unallocated space(4.5 GB) in my windows OS(Bootcamp).i am totally screwed up.
I still hope that i have the MAC OS inside my macbook but unable to boot it up.now i have again unallocated that disk as it was earlier.Please help me.

G'day and welcome to the forums.

Do you really mean you only have 4.5GB free space on the hard drive, or did you mean you are try to enlarge/reduce the size of the BootCamp partition? You cannot do this, without special software such as Camptune. And 4.5GB is not big enough to partition. Remember to have at leastv 20% free space on your hard drive for it to work anywhere near peak performance

When you boot hold down the Option key and see if the Mac OS X partition is shown. If not I can see you doing an erase of the whole drive and a clean instal using Recovery Mode. Here is how to do that downloading a new OS via the 'net. Unless absolutely essential, Windows can be a huge hassle.


https://support.apple.com/en-au/HT201314