How to fix the MBR without overwriting HD and without Recovery CD

You can boot from some LiveCD Linux distribution and use TestDisk. It's an utility to inspect and fix hard drive problems and includes an options to either restore MBR from the backup or generate a new MBR.

If it is a HP Laptop, it already has the maximum 4 partitions allowed, so you cannot create another partition with damaging one or more of the other 4, which you have discovered. So you cannot do what you want, use an external usb hard drive to store your data.

HP uses a custom Master Boot Record, using a recovery or regular Windows disc to fix the MBR will break this custom MBR, then your factory restore partition will not work.

HP has no easy method to repair the custom MBR other than do a full restore from the restore partition or HP recovery media. So back up your data and do a HP recovery.

I suggest you make your HP recovery media asap, label them appropriately and store in a safe place. http://support.hp.com/us-en/document/c01867124?jumpid=reg_r1002_usen_c-001_title_r0001

Also make this disc http://h20564.www2.hp.com/hpsc/doc/public/display?docId=emr_na-c02058933&DocLang=en&docLocale=en_US&jumpid=reg_r1002_usen_c-001_title_r0001

If you did not make your recovery media and cannot boot the PC: You may be able to find HP recovery discs here since HP no longer offers them.

http://www.computersurgeons.com/Default.aspx

Also see this but W7 recovery media is no longer available from HP. http://support.hp.com/us-en/document/bph07143

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You could borrow or download a copy of Windows Home Premium SP1 - just downloading the image is legal as far as I'm aware. Using this to boot into Windows Recovery console you would use the fixmbr command.

Instructions (taken from here)

1. Insert the Windows 7 installation DVD and boot from the DVD drive. While in some older systems you may have to change boot order through system BIOS, most newer systems allow booting from DVD without changing boot order by simply clicking on any key when prompted to doing so.

2. Choose your default "Language", "Time", and "keyboard Input" on the first window and click next.

3. You're now presented with three choices.

   • Click on "Repair Your Computer" to gain access to the System Recovery window.

   • Now choose "Command Prompt" in order to run the desired utility which is called "bootsect.exe". Bootsect is located inside the boot folder so change your directory to boot.

   • Now run bootsect /nt60 C:\ if you had Windows 7 initially installed in the C partition.

     • Alternatively, you can run bootsect /nt60 SYS or bootsect /nt60 ALL to repair the system partition or all partitions.

   • Eject the DVD, and restart the computer. Your computer should now boot Windows 7 again.

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