For e.g. You should be able to recover all data in case of
1) Windows acting up due to virus infestation
2) Accidentally deleting critical windows installation files there by rendering windows un bootable
3) Accidentally modifiying boot.ini to render windows un bootable.
4) BSOD due to missing boot.ini, improper or wrong driver installtion
This procedure will have varying degree of success in case of
1) Hard disk developing bad sectors and there by rendering windows installtion unbootable
2) There is a mechanical/electronic failure on the hard disk
The things that are required:
1) A computer with a working CD/DVD drive windows you can't boot into
2) A Linux Live CD (I am going to use a Ubuntu Live CD)
3) a Portable harddisk with atleast the free space that will be required for the data being recovered
4) Basic knowledge about BIOS and features
Please note that it is very important to perform this procedure before trying to write anything on the windows installation partition (Reparing windows in OK). If you have already tried to format the re-install, chances of data recovery may be very small. Also any linux installation (Puppy, knoppix, ubuntu, fedora) can be used as long as they support booting from live Cd. alternatively you can also a Live USB. Procedure for making a Live usb can be found at:
1. for ubuntu: https://help.ubuntu.com/community/Installation/FromUSBStick#Installing%20Ubuntu%20directly%20on%20a%20USB%20flash%20drive
2. For knoppix: http://www.knoppix.net/wiki/Bootable_USB_Key
Step 1: Setting First Boot Device As CD/DVD/USB Drive
Assuming that you have all the resources at hand, let us get started.
Please note that the motherboard options for entering into BIOS setup may be different for different manufacturers and Laptops.
1. Start your computer. During POST, note the button that needs to be pressed for BIOS setup utility. In my case, it is the "DELETE" key. Press the delete key to enter BIOS setup
Step 2: Setting Up First Boot Device As CDROM/USB
2. In the bios setup sceen. Navigate to "Advanced BIOS features" using direction keys and press enter. You should now see the advance bios features screena and the boot priority of Devices. navigate to "First boot device" and press enter. Select CDROM. Press Enter.
3. Press Escape to escape from advance bios features options and go to BIOS setup initial screen. Now Navigate to "Save & Exit Setup" Press Enter, When asked to save changes to BIOS, press Y for Yes and Enter. The computer will restart. Insert the Linux LIVE CD in the drive.
Step 3: Booting From Linux Live CD
If the computer boots from the DVD, you should see the Language selection screen. My preferred language is english, so highlight the option and press Enter.
In the next screen, Select "Try ubuntu without making any change to your computer" and press enter. The selection if already not selected will have to be done by direction keys on keyboard
Ubuntu will then go about booting from the DVD.
Step 4: Recover Data After Ubuntu Has Booted
Right click > Copy the data from that partition and Right click > paste it on to another partition or preferably a USB portable harddisk. use portable hard disk if you suspect that your hard disk is failing. Let me remind you that it might be your last chance to retrieve data before the hard disk dies.
Once the data transfer is complete, navigate back to the desktop and select shutdown.
You can now go about formating and installing new data, being sure that the data has been backed up.
However i cannot stress enough the importance of having a back up. always create a back up regularly.