Firstly, DON’T PANIC! YOUR INFORMATION IS (PROBABLY) STILL THERE!!!
DISCLAIMER: READ THIS OVER BEFORE ATTEMPTING. Also, try at your own discretion. I am not responsible for you f’ing up your computer.
What this How-To will address:
- I’ve tried to add a partition on the drive containing my Windows 7 / Vista installation, and now when I start up my computer I get the message ‘Missing Operating System’
- I accidentally deleted my system partition (contains your partition table and MBR)
What caused it?
Your computer has at minimum 2 partitions:
- One is the system partition where your Master Boot Record and boot table reside. Basically, when your computer starts up, it goes there, and asks where Windows is installed. The MBR tells it.
- Another is your boot partition. This holds Windows.
Windows 7 and Vista have a different system partition structure than their predecessors. I used Paragon Partition Manager to split my 1 TB drive with Windows 7 installed on it into two 500 GB drives – only one with Win 7 on it. Paragon wrote over my system partition and wiped out the information saying where my OS was. When I viewed my system partition, it appeared to be ‘unpartitioned space’
What to do:
- On another computer, download Paragon Backup & Recovery (you can get the 30-day trial for free). Burn this to a CD.
- Boot up your computer from the Recovery CD (you may need to change the boot order in BIOS so that it boots from a CD-ROM before the HDD)
- Browse onto your drive, ensure your files are there. Use their tool to backup your files onto an external drive or DVDs. It essentially creates an image. You should probably use their tool to copy your files over too incase these next steps don’t work.
- Note: I tried other methods, namely downloading software to re-create the system partition but this didn’t work, likely because it was trying to access an unformatted partition. When I formatted the system partition to NTFS like it should be and then tried to recover the system partition, again it did nothing.
- Now reboot your computer and boot up with your Windows 7 / Vista CD and delete all the partitions, partition the drive the way you want it, and then install Windows 7. (I created two 500 GB partitions, then installed Win 7 on one of them. This automatically created a System Partition before these two 500 GB partitions and shrunk them by some trivial amount).
- Once Windows is installed, reboot your computer and make sure it will go into Windows. (If you are still getting Missing Operating System, try everything again, otherwise you may have an f’ed up drive).
- Then reboot again, but this time boot into the Paragon Recovery CD. Using this software, restore your Windows 7 installation from the backup image you made onto the external HDD.
- Once this is done, reboot again. Windows will come up with a message saying it is checking the system partition or something like that. Once it is done, you should be back into your Windows installation and it’ll all be as if nothing ever happened. If not- at least you had your files backed up to that external HDD and a fresh Windows installation. You’ll have to copy them over and download all your fav programs again, but at least your files are there.