How can I reinstall OS X without signing to App Store

If you decide to purchase 10.8 after installing and updating 10.6 then consider making yourself a bootable 10.8 installation flash drive for future needs..

http://www.macworld.com/article/1167857/how_to_make_a_bootable_mountain_lion_ins tall_drive.html

http://reviews.cnet.com/8301-13727_7-57479690-263/how-to-create-an-os-x-10.8-mou ntain-lion-install-drive/

http://subrosasoft.com/blog/guide/create-a-bootable-mac-os-x-10-8-mountain-lion- installer-flash-drive

I only forgot one thing, this version of system was bought by my friend and with his Apple ID.

You can't reinstall Mountain Lion without knowing your friend's Apple ID and password. In other words, you had been using an illegal copy of ML. You need to purchase your own. It's only $20. Apple will not help you reinstall ML from another user's account.

Since you do own Snow Leopard, you have to do a two step reinstall to get back to Mountain Lion.

1) Insert the Snow Leopard DVD and boot to it by restarting and holding down the Option key. Once the screen to choose a startup disk appears, choose the DVD and install Snow Leopard onto the hard drive.

2) Once the install is complete, your Mac will be 10.6.3 at the newest since that was the last version released on disk. You must then download and install the 10.6.8 Combo Update to get the App Store installed.

3) Launch the App Store and login with your Apple ID and password, which is the same one you use to login to these forums. Purchase Mountain Lion. It will download and automatically launch the installation. With a legal copy under your Apple ID, you will always be able to get it again in the future without paying for it again.

I purchased the snow leopard on app store so sadly I do not own it´s DVD.

You cannot possibly have purchased Snow Leopard on the App Store since the only way it is legally sold is on DVD. There is no download version available that is not an illegal distribution.

I don't know what you have for Snow Leopard, but I wouldn't use it for any reason under the sun. Illegal copies are loaded with malware. If that's okay with you though, then go ahead and reinstall it.

Otherwise, purchase Snow Leopard from Apple. Install that, then use the App Store to purchase and install Mountain Lion.

How did you reformat the hard drive?

If you used "recovery" to do that, can you not use recovery to reinstall?

That being said, you will need your own copy of OS Mountain Lion for any trouble shooting in the future. Which means you will have to create an account on the App Store, and pay $20 for it. That is the easiest route.

Isn´t there any way to downgrade without the dvd?

No.

What did your Mac originally come with? If it shipped with Lion, then you cannot install Snow Leopard at all. Instead, restart and hold down the Command+Option+R keys to do an Internet Recovery. This will download the entire version of Lion your Mac shipped with and reinstall it. It will also create a new Recovery partition.

If your Mac shipped with Snow Leopard and you have misplaced the original gray disks, you will need to purchase a new set of disks from Apple. Especially if it shipped with 10.6.4 or later. No retail version will work on your Mac. Apple will ask for your Mac's serial number to ensure you get the correct replacement disks.

In either case, once you have a working version of OS X installed, you can then purchase Mountain Lion via the App Store.

The only system you could have bought from the store is LION. As Kurt says, Snow leopard was never available in the App store. In fact it was virtually discontinued soon after the App store was launched and then resurrected when Apple realised that it was a necessary assist to underwriting the App store's facilities.

I suggest that you contact Apple customer support and order OS replacement disks for your Mac. Have your serial number ready and there is a charge.

This will allow you to install the original OS and you may proceed from there.

Ciao.

Since Lion is installing from a Command+Option+R start to a bare drive, then that must be what your Mac came with. It wouldn't install that way otherwise. So don't purchase Snow Leopard. You won't be able to use it.

Try this:

http://www.apple.com/support/mac/app-store/contact/

What are you using to post here?

How did you format the drive on the Mac?