After installing Windows 8.1, I couldn't see/access OS X partition

I went successfully installing Windows 8.1 using Bootcamp instructions, but unfortunately, unlike my old MBA, when the Windows boots up, I couldn't neither see nor access the Mavericks partition, it's just showing the Windows partition.

I tried the below drivers (where my rMBR Late 2013 is mentioned), and it didn't work as well:-

http://support.apple.com/downloads/DL1721/en_US/BootCamp5.1.5640.zip

Also, I tried that other version, and didn't work:-

http://support.apple.com/downloads/DL1720/en_US/BootCamp5.1.5621.zip

Finally, I installed MacDrive software, and surprisingly didn't work :-(

Plz help.