OS X Snow Leopard Looking for an explanation for an DIY Harddisk data recovery procedure

Question

Hi There,
Yesterday my 13" Unibody MacBook (A1278) popped up an "Invalid B-Tree Node Size" Mac OS X Error. searching the internet for on a solution and explanation so far gave me headaches. And did not provide me guidance for an proper Do It Yourself procedure. Off course I want to have data recovered for which no backup is available (a forced clean install now is not an option!). When booting with the install DVD and then using Diskutility fails (yes the simple recovery does not work in my case). I read about using third party software solutions (e.g. data rescue or DiskWarior) but the how to is not clear to me, which steps need to be performed ? How can such an data recovery process be performed ? What sort of hardware or wires are needed to do this ? The only Apple Machines I can use now are a other 15” MacbookPro  and an Windows XP desktop. I bought a Sharkoon SATA Quickport XT (USB3) but this product is still wrapped because I am not sure it will (or I will get it to) run under OS X. So again can anyone provide me a walkthrough for such a (troubleshooting) HDD data recovery process?
The data that needs to be recovered concerns foto's and PhD writing material in the end process of some to be published articles.
Thnx in advance for your comment!

Answer 1

First order of busness is to get your data off the 13"
If this data is of extreme importance, your better off letting a professional computer support specialist handle it.
Do not use Disk Warrior yet, it could make matters worse. Your data needs to be recovered and it can be provided nothing further is done to the drive.
The first 3 methods below are designed to be passive, just trying to read the data and get it safely off the hard drive first.
There is no need to extract the hard drive from the computer yet. This in itself can cause further damage.
1: Unwrap the Sharkoon SATA Quickport XT USB 3 and stick a blank internal drive in it.
If you don't have one, then return that device and/or get yourself a external powered USB 3, 2 or 1 (3 is backward compatible with 2, 1) hard drive, runs about $100 for a 1TB drive.
Hook this drive up to the 15" MacBook Pro and in your Utilities Folder is Disk Utilities.
Select this new drive and Erase > format it HFS+ Journaled with Security Option > Zero all data. (going to take a bit to complete)
2:  Use the Windows PC or the 15" MacBook Pro to download a ISO copy of PartedMagic. Burn it to a blank cd using Windows 7 right click and burn, or using the free ImgBurn for Windows. Or using Disk Utility on OS X.
http://partedmagic.com/doku.php?id=screenshots
Hook up the now finished USB external drive (or the Quickport) to the 13" MacBook and power up.
Once the cd is burned, stick it in the MacBook and reboot holding option and c, keep holding and you will have a option to load into RAM. DO so and the disk will spit back out.
In the screen on the left is a icon called MountDevices, doubleclick it twice to get two file transfer windows. Use the third window to mount your disks. Use the two file transfer windows to navigate and transfer your files off to the external drive using drag and drop methods.
Once that's completed, unmount the drives and use the lower left corner to exit. Reboot.
Take the external drive to the 15" MacBook Pro and verify your files are there.
3: Another method if the PartedMagic cd doesn't work, is to c boot off the MacBook install disks on the MacBook, use Disk Utility to format the external drive HFS+ Journaled and install OS X on it. It might be hold option bootable, but I'm not sure if older machines can boot from a USB, usually it's Firewire for them and you don't have Firewire.
Last would be to extract the hard drive from the computer if it's easily done through the battery port then stick it in the SATA Quickport port and hook it up to the 15" and transfer your files off.  If your having disk reading errors, then on the 15" MBP download and install DataRescue, it will read the files directly via the 1's and 0's of the files themselves. Data Rescue and other recovery software needs another drive to send data to, can't recover back to the problem drive.
http://www.prosofteng.com/products/data_rescue.php
Once the data is off, you can hold c, boot from the OSX install disk for the MacBook and from the utilities menu select Disk Utility and erase (with Security option Zero all data) and format the drive HFS+ Journaled and quit, reinstall OS X again. Or you can try using Disk Repair/Warrior and see if that works. (only works from another boot drive/disk). Or use the 15" to format the drive and stick it back into the 13"