Mid 2010 Macbook Pro (7,1) - Downgrading from Mountain Lion (10.8.3) to Snow Leopard

Hi everyone!

I am looking for some help with downgrading my macbook pro from ML back down to SL. I'll start off with some information about my case:

I bought this computer mid 2010 - I believe in July, if that matters. It is a Macbook Pro 7,1 model. The computer came with two disks, one being the Snow Leopard 10.6.3 install dvd, and the other being the applications install dvd. I do still have these dvd's, sitting beside me as I type this. Just like many others, I upgraded my computer to Lion, and from there went to Mountain Lion. I have been on Mountain Lion for several months now, currently running 10.8.3. I know a lot of you out there are disappointed with this OS, and many have experienced significant adverse effects on the overall performance of their computer. That being said, I also know that a lot of you have not had these sorts of issues running the OS. As you can tell, I mysef fall into the first category, as I have not had the greatest experience with it. It just seems to tire out my computer at activity levels which, on Snow Leopard, would not be problematic. I say tire out here in that my computer will overheat, slow down, and even sometimes crash (the crashes primarily begin with the spinning rainbow wheel, attempts to quit / force quit the applications I am running, followed by complete and utter frozenness). When this happens, I have no choice but to press the power button until the computer shuts off, then I restart, occasioanlly taking multiple attempts because of kernel panics the first one or two times. Who knows why this happens...I upgraded my RAM a couple months ago from 4GB to 8GB, which has seemed to help some but not fix the problem entirely. So, I have been wanting to downgrade back to Snow Leopard.

Ok so, I have made multiple attempts at this. For starters, I can tell you that the computer simply will not boot from the Install DVD (it is the one which came with the computer, not a retail version or anything like that). Additionaly, I cannot restore the SL DMG file from the dvd, neither to my hard drive nor to a USB drive. Because of this, I ended up trying this: I downloaded the snow leopard installation files (I believe just the content of the DVD ripped from the disc) via a torrent. I then got a 16 GB USB flash drive, wiped and formatted it (Mac OS Extended (Journaled)), and copied to the USB drive the install file I downloaded. I'll also note that I have done the same thing for Mountain Lion, copying the install file from the app store to a separate 16 GB USB drive. Ok, onto the results of my attempts at downgrading:

Each time I have tried to downgrade, I have taken the following step:

1) Power down the computer

2) Insert Snow Leopard USB drive

3) Boot up the computer, holding the option/alt key

4) Selecting the Snow Leopard USB drive

-It would successfully boot from the USB, and would bring me to the language selection window, as expected

5) After selecting English, the window gives me the option to continue with the install, or access any utilities, and I would go to Disk Utility

6) I selected the internal drive in Disk Utility (the whole drive, not the indented partition), and I went to the partition tab, partitioning the drive to have 1 partition, Mac OS Extended (Journaled), erasing the current partition

**Note: I have not tried this, but I feel like maybe If I were to first Erase the drive, opting to zero out all data (1 pass) in the security options, then partition the drive the same way as I did in step 6, perhaps the installation would go smoothly without returning any errors...thoughts?

7) After step 6, I would return to the install os x window and begin installation of snow leopard.

-Every time I have done this, the install has returned an error about mid-way through, and I would be prompted to restart and try installing again

8) Now having a non-booting computer, I would end up powering down, swapping out the snow leopard usb with my mountain lion usb, booting from that, partitioning the drive the same way as before, and reinstalling mountain lion

-This beings me back to square 1. A working, booting computer on Mountain Lion...

I believe that my issues surrounding the use of my install dvd (that came with the computer) are caused by a bad optical drive. When in mountain lion, if I insert the dvd, it will read it, but it will do so very slowly. For example, after inserting the dvd and the install os x window coming up, if I select optional installs or instructions, each of these folders would open, but take a very long time to display their contents. It also is a struggle to get the disc to eject in this situation.

So, if anyone has had a similar situation and came out on top, I would truly appreciate your help!

Thanks guys,

Nick