remove windows and install mac osx 10

Boot from another drive or from the discs that came with the computer when it was new. Use Disk Utility to erase the internal drive. Use the installer to restore OS X to the drive. If your computer is a 2011 model or later then you can do the following:

Install OS X Using Network Recovery

Be sure you have backed up your files because the following procedure will remove everything from the hard drive.

Boot to the Network Recovery Server:

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 newly installed hard drive (this is the out-dented 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 Apply button and wait until the process has completed. Quit DU and return to the main menu.

Reinstall OS X: Select Reinstall OS X and click on the Continue 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.

This should restore the version of OS X originally pre-installed on the computer.

For Snow Leopard or earlier:

Clean Install of Snow Leopard

Be sure you have backed up your files because the following procedure will remove everything from the hard drive.

1. Boot the computer using the Snow Leopard Installer Disc or the Disc 1 that came

with your computer. Insert the disc into the optical drive and restart the computer.

After the chime press and hold down the "C" key. Release the key when you see

a small spinning gear appear below the dark gray Apple logo.

2. After the installer loads select your language and click on the Continue

button. When the menu bar appears select Disk Utility from the Utilities menu.

After DU loads select the hard drive entry from the left side list (mfgr.'s ID and drive

size.) Click on the Partition tab in the DU main window. Set the number of

partitions to one (1) from the Partitions drop down menu, click on Options button

and select GUID, click on OK, then set the format type to MacOS Extended

(Journaled, if supported), then click on the Apply button.

3. When the formatting has completed quit DU and return to the installer. Proceed

with the OS X installation and follow the directions included with the installer.

4. When the installation has completed your computer will Restart into the Setup

Assistant. After you finish Setup Assistant will complete the installation after which

you will be running a fresh install of OS X. You can now begin the update process

by opening Software Update and installing all recommended updates to bring your

installation current.

Download and install Mac OS X 10.6.8 Update Combo v1.1.

Did your OSX stop working after the Windows installation was complete? Is Windows a new and recent installation? Is it possible that you chose the incorrect partition as a BC/Windows destination? Did you use Windows Disk Management snap-in to make any changes to the disk partitions?

You turned a GPT Disk with OSX and Hybrid MBR to a MBR only disk, from which OSX will never boot. It is possible to fix it.

Please install OS X on an external disk and boot from it - How to install OS X on an external drive connected to your Mac - Apple Support . Try and use the same version of OS X as you have on the internal disk to avoid issues. You can do this using Internet Recovery - OS X: About OS X Recovery - Apple Support .

Install GPT Fdisk once you have the external disk OS X working - http://sourceforge.net/projects/gptfdisk/ .

Post back when you have booted from the external boot disk.

If you have a second Mac and appropriate adapters as noted in - Share files between two computers with target disk mode - Apple Support - then Target Disk Mode ca also be used to fix your non-workign Mac.

Kappy - it seems the internal disk has a corrupted GPT and thinks it is Windows LDM disk. Let us see if I can fix it.

Shutdown your Mac, power it up and hold Command+Opt+R. This should bring up Internet Recovery. You can install OSX on the external disk and then boot from it. 16GB USB is fine, but it may be a bit slow.

You do not need one. If you have a USB, it can be formatted within Internet Recovery to allow OS X Installation.

Another option is to download the Windows version of GPT Fdisk to correct the issue.

http://sourceforge.net/projects/gptfdisk/

Assuming you put Gdisk in Downloads folder, open a CMD window with Admin rights in Windows. CD to the Downloads folder and type

gdisk64.exe 0:

Do not double-click on gdisk64.exe. The number after gdisk64.exe is the digit zero followed by a colon. This indicates disk 0. It will look similar to the following.

If you see a question about MBR or GPT, choose GPT . Use Windows Snipping Tool to post screen shots to Apple Discussions.

Your CMD Windows needs Administrative privileges to work.

Your GPT was corrupted by Windows LDM. You do not need to re-install Windows or OSX. This can be corrected.

Can you use Re: After installing windows10 using Bootcamp can't boot in to OS X as a reference and

use your specific values for GPT 1-4 only. Do not use the values in the reference when recreating the GPT.

If you are not comfortable, I can provide the exact commands.

Third-party tools are notorious for causing problems. You are already running Gdisk. Creating a new GPT with the appropriate start/end is the recommended way to go. It is the quickest method to recover your data, without re-installing any OS.