Mac OS X Mavericks Setup file Retrieve Is there any possibility of getting the OS X Mavericks installation file after OS X Mavericks is installed? I need to use it on another macbook.

Or is there anyway to retrieve it?
If the app itself was lost, you can always re-download it from the App Store. For installing on a second computer, I'd make a flash drive version of the install. You can follow this guide for creating the flash drive install from this guide.