I want to install snow leopard on my macbook pro 17" mid 2010, but the last firmware update seems not allowing me to do it. How can I solve this problem

Anyone selling or distributing any Mac OS version (except Apple) is doing so illegally (see link to SLA below). Now, I may not like it or agree with the terms either, but I do prefer not violating legal contracts and that is what you and I and everyone else agree to when you buy/download/install software. So, according to the licensing agreement, the software cannot be sold or given away unless you include the install media with a computer you are selling. And, if you got it from the app store, the terms are even more restrictive. Again, I may not like it, but I also understand that it is a company's property and they can put any restriction they like on it. If you feel that is too restrictive, then simply do not use it.

FWIW, I would not purchase any computer which 1) has not been erased and have the original OS installed, and 2) does not have the required original install media if it came with one. One just creates too many problems for oneself.

So, get yourself a legal copy of SL, install it onto an external drive, boot from it, erase your internal, and clone the SL system to it.

Snow Leopard:

http://images.apple.com/legal/sla/docs/osx_snow_leopard_sec_upd.pdf

Sierra (as an example of a download only OS):

http://images.apple.com/legal/sla/docs/macOS1012.pdf

Greetings. I have a MBP 17" Mid 2010, bought it second hand so no System DVD was included, and recently had the same problem. I spent a couple of days going through all the various suggestions found online. Here's how I solved the issue, hopefully it can still help other users.

- I downloaded a retail Snow Leopard 10.6.3 dmg (installer version 23.1.1, check installer Info if you have doubts) - and yes, I think it was ok for me to download it since my notebook was originally supplied with that OS,

- created a bootable USB stick with it (guides about how-to are common so I won't waste your time repeating the procedure here),

- connected an external hd and erased the content while still on Sierra,

- replaced the internal hd with the new empty one,

- booted from the USB stick,

- initialized the hard drive again, just to make sure, using Disk Utility included in the SL installation,

- launched the installer.

All went smooth and after some 10 mins the new/old OS was successfully installed. I'm now using Snow Leopard 10.6.3 to write this reply.

Things were easier than I thought while reading many forums. I guess a lot of people just throw in their answers without direct knowledge (and this actually makes everything quite annoying and only rarely really helpful so, guys, think twice before you answer: either you DO KNOW what you're saying OR you're complicating things / just wasting your and other people's time).

Note: while I was on Sierra, the SL installer's icon appeared with the typical sign indicating that it wouldn't work. But it did.

Mafomo wrote:

- I downloaded a retail Snow Leopard 10.6.3 dmg (installer version 23.1.1, check installer Info if you have doubts) - and yes, I think it was ok for me to download it since my notebook was originally supplied with that OS,

Snow Leopard has never been available for download. You have used a pirated version of Snow leopard which is not legal.

Ciao.

I had a 2010 and it was extremely difficult to reinstall Snow Leopard before selling it. I was told by Apple that the firmware update to allow internet recovery made the option of booting and reinstalling SL impossible. I was only able to get it back to SL because I had made a complete clone of my system - I booted from the clone, wiped the drive, and cloned the clone back. I also did some extensive testing with this scenario at the time and found that using internet recovery and erasing the drive may (3 tries out of 5) install Lion (since that was the first OS available online) - the other two times it refused to do anything. So, you can try creating a clone from SL, boot from it, and then clone (don't try to install) that entire thing back with CCC. Or you can try to install Lion with internet recovery (which was not the best OS I've ever seen).

I have legally bought the MBP and it has been given to me without the dvd. I could have asked a friend to duplicate the dvd for me (which I'm sure in your opinion is not legal too) but the net made things faster and easier. Maybe mr. Pedant thinks I should have slapped my own forehead and thought "hey, let's give mama Apple some more bucks for a OS that came with the package otherwise - oh my God - it's "illegal". C'mon. Sometimes I wonder whether there's some kind of value in posting useless (and pedant) comments... Now go ahead, post another one, I promise I won't reply.

A Mid 2010 MacBook Pro would have shipped with Snow Leopard. What happens when you attempt an install?

Could you be more descriptive of the problem? This shouldn't have a thing to do with firmware. What version of Snow Leopard are you trying to install? You must use the installer disc that came with your computer. The retail Snow Leopard DVD will not work.

In order to reinstall Snow Leopard you will need to boot from a Snow Leopard DVD, the one that came with your computer. Do you have it? If so:

Booting From An OS X Installer Disc

1. Insert OS X Installer Disc into the optical drive.

2. Restart the computer.

3. Immediately after the chime press and hold down the "C" key.

4. Release the key when the spinning gear below the dark gray Apple

logo appears.

5. Wait for installer to finish loading.

Drive Partition and Format

1. Boot from your OS X Installer Disc. 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.

2. After DU loads select your hard drive (this is the entry with the mfgr.'s ID and size) from the left side list. Note the SMART status of the drive in DU's status area. If it does not say "Verified" then the drive is failing or has failed and will need replacing. SMART info will not be reported on external drives. Otherwise, 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.

4. When formatting is done quit DU and return to the installer. Complete the Snow Leopard installation.

That firmware update only enables your model to use Internet Recovery. If you cannot boot from your installer DVD that came with the computer then the problem is likely with the DVD or the optical drive. I suggest you try thoroughly cleaning the DVD with a lint-free cloth and rubbing alcohol.

You can also try cloning the DVD to an 8 GB USB flash drive properly partitioned and formatted, then try booting from the flash drive using OPTION boot:

Boot Using OPTION key:

1. Restart the computer.

2. Immediately after the chime press and hold down the

"OPTION" key.

3. Release the key when the boot manager appears.

4. Select the desired disk icon from which you want to boot.

5. Click on the arrow button below the icon.

You cannot downgrade firmware updates. As I said the last one for your computer has nothing to do with the optical drive or booting from a DVD. If you have the DVD that came with computer, then you should try the options I've provided.

Why must you reinstall Snow Leopard? Is there a particular reason you can't reinstall Lion since that is what you were running?