Guys today i really messed up installing Backtrack 4 on my portable USB drive and couldnot find a way to revert back the harmful changes. Here’s my story (in short ) I tried to install the Backtrack 4 from live DVD to my 8Gb Pendrive so i simply boot up using the Backtrack 4 Live DVD and clicked install icon (only icon) available on desktop.As Backtrack 4 is Ubuntu based Linux Distro so i thought i’ll revert back any harmful changes if required but little did i know that i am going to encounter annoying GRUB errors messages.So Every thing went fine and it took me nearly 1 hour to install the Backtrack 4 on Pendrive (which never boots). I just restarted the pc and was hoping to boot straight into Backtrack 4 OS using Pendrive but couldnot as what i’ve did was completely wrong. Now by this time i knew my experiment failed miserably so i was looking for a way to revert back the changes. I removed the Pendrive and reboot the computed and Bang…. GRUB error 25 (sometimes it was Grub error 21) and When i reinserted Pendrive i was greeted with GRUB error 17. Below is how i managed to make my XP boot normaly like it was earlier.
Follow the step below to correct
Grub error 17
or
GRUB error 25
or
Grub error 21
s:
Steps:
1. Remove Backtrack 4 DVD and Pendrive (if any)
2. Insert XP Professional bootable DVD and boot through it
3. When it asks to repair “Select Repair” by pressing R on keyboard and when it asks for what windows partition to repair , select the one which you think is affected by entering the order number eg. 1 or 2 .
4.You’ll be greeted with command window and then type “fixmbr” , and hit enter
Dont worry i know its scary to ready if the partitions may become inaccessible.But just dont worry as it will only repair the corrupted MBR on C drive.
5. Reboot and Enjoy else complain here again.
I hope linux newbies like me may find this tutorial useful.