Operating System Recovery

MS Windows, MAC from Apple, Linux as well as any other operating systems, your computer was ran by before crash, make no difference for the sequence of data recovery procedures. Regardless particular OS we must retrieve as much bytes of information as possible from each sector of failed media, whether it is a single hard drive, or group of drives organized in array (RAID systems).
Then we start data reconstruction process to make files and folders look just the way they were on your computer before disaster happened.
Most customers are not requiring the system recovery as such, rather only file recovery for that particular OS. For example, if you need your pictures and documents transferred to freshly installed MAC OS X Snow Leopard, Tiger, or Panther, then your recovered data onto spare media will be organized like this, when you receive it back:

The same files recovered for Windows XP have slightly different location:

Most likely, by the time the data from damaged hard drive are restored, you will already have your new hard drive and operating system up and running on your computer. Then you just copy recovered data to your computer into the same locations, or wherever you like it to be copied. Make sure that all software applications are installed as well, before you start working with you files.
On the other hand, there are always customers who would expect the full system recovery in its true meaning, where the drive-clone is to boot on the same computer of the original failed hard drive. However, we need to mention that not each drive-clone is bootable after recovery. In some cases the extra system tuning yet will be required, such as special utilities for the system repair on Windows setup CD. Once the booting from the drive-clone is successful, there is no need to re-install any programs, including OS, mail client, or accounting system. Just like hard drive crash never occurred!