I installed Windows on my MacBook Air 2015 and erased the SSD in the process because it's only 128 GB and because I thought it would be easy to create a bootable USB key to reinstall OS X should I need to do that.

I then found out that power management under Windows is lacklustre to say the least. Right after that I had to realize that creating a bootable USB key from Windows is difficult to say the least requiring (paid) third party software. What is most strange though is how difficult it is to get the actual file from a Windows PC. I had to download one for OS X El Capitan from a shady website.

The stick I created with TransMac did not show up as a boot option even though I made sure it was formatted the right way (as per an online guide). Internet Recovery gives me error "-4403F" which Google doesn't seem to know.

So I'm stuck.

My question is if any Apple Store (I'm in Germany now but will be in Thailand next week) will reinstall OS X for me on the spot (as I would think they'd do) if I just walk in with my laptop?

  • 1
    I'd say it depends on how busy the store is whether or not they'd do it on the spot, however within an hour or two at a busy store. BTW Aside from the possible legal issues involved in your acquisition of OS X in the manner you described, you leave yourself open to all sorts of security issues downloading OS X other then legitimately via the App Store or having Apple install it. Commented Jul 24, 2016 at 14:23
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    > Right after that I had to realize that creating a bootable USB key from Windows is difficult to say the least requiring (paid) third party software. This is as incorrect as it can get.
    – pratnala
    Commented Jul 24, 2016 at 19:27
  • Perhaps use phone and ask them right now "on the spot".
    – Kyslik
    Commented Jul 25, 2016 at 7:52
  • @pratnala - I think they may be right in the context of making a bootable USB from an OSX disk image in Windows. The only application I know of that does this is Transmac, which while it has a trial version, is a paid app.
    – Logarr
    Commented Jul 25, 2016 at 15:42
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    To make a bootable USB key, use Unetbootin (it's free). Don't pay for that. -- Also, power management is less than desired because Apple deliberately made it that way (on non-Apple hardware, it's a non-issue).
    – SnakeDoc
    Commented Jul 25, 2016 at 16:43

4 Answers 4


YES! You can either make a Genius Bar appointment or you can do a walk-in. If you do a walk-in for the genius bar you may have to wait a bit, but they will do it for free. The instillation may take a little while, so plan on having some free time and a good book (or movie or something - there's free in-store wifi).

Each store typically has good internet and a local caching sever, so you are loading your OS Recovery and install images from the local network which makes it quite fast. Having the Genius Bar close by is just bonus if you don't know what to do or need advanced cleanup.

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    Possible good news is the stores have a revamped walk in service. Many stores have technicians running the queue so they would likely direct you to an area with DC power and you could start the reinstallation yourself with internet recovery. This might be far faster than a network where you can't start internet recovery yourself for whatever reason (assuming the store is close by).
    – bmike
    Commented Jul 24, 2016 at 20:46
  • additionally, the apple store has what they refer to as "restore images" which take about ten minutes to install a brand new OS (and are designed with this scenario in mind - their restore images erase a computer's hard drive and perform a clean install).
    – Valashtar
    Commented Aug 8, 2016 at 2:30

On startup hold Command+Option+R. You can now use Internet Recovery to install OS X. Don't download from shady sites. You are compromising your security this way.


I had to download one for El Capitan from a shady website.

Eeek. I would not trust that, personally.

Do you have access to a good internet connection? If so, you can use OS X Internet Recovery to install a fresh version of Mac OS X via your internet connection, directly from Apple.


I accidently wiped my hard-drive clean and when I tried both commandoptionR & commandR I found my recovery drive had been damaged as well and internet recovery would not complete (I do not remember the error I received).
I was able to get the OS reinstalled at the Apple Store for free. I think your only problem might be getting 'walk-in' service. If there Apple Stores are as busy as the ones in the US getting an appointment well save you a few hours of waiting.

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    Command & OPTION & R does NOT use the Recovery partition but is a firmware feature.
    – bot47
    Commented Jul 25, 2016 at 8:11
  • I thought Command+R was Recovery Drive and Command+Option+R was Internet Recovery? Either way, I tried both of them and neither worked.
    – 345422
    Commented Jul 25, 2016 at 10:04
  • That's right. But Internet Recovery works even with no mass storage installed. That's the point of it.
    – bot47
    Commented Jul 25, 2016 at 11:20
  • Which is what I thought as well. However, cmd+r did not work at all and cmd+opt+r threw an error (about 4 times). I wish I could remember what the error was, but all I remember is it happened after the globe and progress bar where present and including the word 'disk.' But the error is why I ended up going to the Apple Store.
    – 345422
    Commented Jul 25, 2016 at 11:36
  • +1 for "make an appointment" - the store in Oxford Street, London, has about a 5-day waiting list.
    – Tetsujin
    Commented Jul 29, 2016 at 17:13

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