His Mac It’s running slow, so you’ve decided to reinstall OS X but don’t want to lose all your data? No problem All Apple PCs equipped with OS X Lion (or higher) are equipped with a recovery partition that allows you to reinstall the operating system on your PC without using external media (CDs, DVDs, USB sticks, etc.) and without delete data from hard drive
if you want to find out how to reinstall lion without completely formatting the Mac, therefore all you have to do is take advantage of this feature by following the instructions I am going to give you. However, before you start: make a good backup of the most important files on your PC. Nothing will be erased as mentioned, but as we know, prudence is never too much!
if you want to find out how to reinstall lionthe first step you should take is to restart your Mac and hold down the button high on the PC keyboard until the selection menu appears to choose which drive to boot from. If the menu does not appear, try holding down the keys cmd + r rather high.
Now, establish an Internet connection by selecting your wireless network from the dropdown menu choose network (the operation is not necessary if you are connected to the Internet via ethernet cable) and select the recovery partition ( recovery HD ) to boot from there. Therefore, configure the use of the Italian language by clicking on the item Use Italian as your main language in the list that appears and click the button with the arrow to proceed with the installation.
At this point, select the item Reinstall Mac OS X from the menu that opens and click the button Following three times in a row to send your PC’s serial number to Apple for authorization to reinstall Lion. Then accept the terms of use of OS Xby clicking the button I agree for two consecutive times, select the unit MacintoshHD (which would later be your Mac’s hard drive) and click the button install to start reinstalling Lion. After a few minutes, you will be asked to restart your PC.
Then click resume and wait while the OS X setup procedure restarts automatically. After 20-30 minutes the operation should complete and you should be able to access your new copy of Lion by looking for all the data you had before the reinstall.
If, instead, you prefer to perform a clean installation of the operating system by completely formatting the Mac hard drive, I remind you that you can also easily perform this operation by following my guide on how to format a Mac.
