Q: Accidentally Installed Windows And Deleted OS X

Boy, you really screwed up that one. Here's the Internet Recovery you will need to do:

Install Mavericks, Lion/Mountain Lion Using Internet Recovery

Be sure you backup your files to an external drive or second internal drive because the following procedure will remove everything from the hard drive.

Boot to the Internet Recovery HD:

Restart the computer and after the chime press and hold down the COMMAND-OPTION- R keys until a globe appears on the screen. Wait patiently - 15-20 minutes - until the Recovery main menu appears.

Partition and Format the hard drive:

1. Select Disk Utility from the main menu and click on the Continue button.

2. After DU loads select your external hard drive (this is the entry with the mfgr.'s ID and size) from the left side list. Click on the Partition tab in the DU main window.

3. Under the Volume Scheme heading set the number of partitions from the drop down menu to one. Click on the Options button, set the partition scheme to GUID then click on the OK button. Set the format type to Mac OS Extended (Journaled.) Click on the Partition button and wait until the process has completed. Quit DU and return to the main menu.

Reinstall Lion/Mountain Lion. Mavericks: Select Reinstall Lion/Mountain Lion, Mavericks and click on the Install button. Be sure to select the correct drive to use if you have more than one.

Note: You will need an active Internet connection. I suggest using Ethernet

            if possible because it is three times faster than wireless.

Sounds like you accidentally gave the whole drive over to Windows. You're going to have to startup using Command+Option+R to do an Internet Recovery. You'll get the minimal screen as a normal Recovery startup. Use Disk Utility to repartition the drive as Mac OS Extended. Then quit Disk Utility and reinstall the OS. It will take a while as the entire OS will need to be installed via the Internet from Apple's servers.

what should be the size of external drive ?

At least the size of your computer's drive.

Hi, i followed your instructions, when it comes to installining it wants my apple id, when i type in my id it says temprary not avaible try again.

what should i do, and i cant use my laptop anymore becuase there is no window in it, i had window 7 but now its deleted.

help please

Hello,

I have this issue too.

When this will be available?