How to restore macOS after windows setup?

Start by using Boot Camp Assistant to remove the Windows volume and rejoin the space to the OS X volume.

Install Sierra or El Capitan from Scratch

1. Restart the computer. Immediately after the chime hold down the CommandandRkeys until the Apple logo appears. When the Utility Menu appears:
2. Select Disk Utility from the Utility Menu and click on Continue button.
3. When Disk Utility loads select the volume (indented entry, usually Macintosh HD) from the Device list.
4. Click on the Erase icon in Disk Utility's main window. A panel will drop down.
5. Set the Format type to Mac OS Extended (Journaled.)
6. Click on the Apply button, then wait for the Done button to activate and click on it.
7. Quit Disk Utility and return to the Utility Menu.
8. Select Reinstall OS X and click on the Continue button.

Use BCA to create your desired Windows volume. Reinstall Windows taking care not make the same mistake as before.

Do you want to 'remove' Windows or do you want to boot back into OS X?

Please also see Boot Camp for Mac: Remove Windows from your Mac .