Critical: How to fix MBR on Ubuntu/Vista dual-boot laptop?

September 21, 2008 4:45 PM

How to I re-install, configure, or set the MBR on my laptop?

I have a Sony VAIO VGN N series laptop. I recently partitioned and installed Ubuntu (Hardy Heron) successfully. Previously I had a Ubuntu/Vista dual boot using the default Ubuntu GRUB that was automatically installed during the setup. But I used EasyBCD in Vista and accidentally uninstalled the Vista Bootloader MBR. Now when I start up my computer all I get is something like "NTLDR not found Press Ctrl+Alt+Del to restart." In other words I have neither the Ubuntu GRUB or Vista Bootloader MBR working. How do I fix this so I can go back to dual-booting both systems? Please help!

posted by meta.mark to computers & internet (4 comments total)

Boot with the Ubuntu LiveCD and reinstall grub (here are some instructions). All should be well!
posted by cdmwebs at 5:27 PM on September 21, 2008

Is your ntldr actually MIA? It's just a file in C:\, though it's hidden so your explorer has to be set to show all files in order for you to see it. Or you can check in a command window. (This is XP SP3):

C:\>attrib -s -h ntldr

C:\>dir ntldr

06/09/2008 08:30 PM 250,048 ntldr
1 File(s) 250,048 bytes

If it's actually gone, you can just copy it over from another system with the same OS (and maybe the same service pack level also, just to be safe.)

If you really have a problem with your master boot record you can write a clean new one with fixmbr, but that will cost you your Ubuntu install.
posted by jfuller at 6:27 PM on September 21, 2008

The NTLDR not found message seems to mean that the disk is not readable to windows--like that there is an MBR problem. It's not that the file has gone missing; it's just the first thing found missing.
posted by hexatron at 7:16 PM on September 21, 2008

Super Grub Disk is a lifesaver when it comes to MBR problems. Simple and tiny download, burn to a disk or what have you, boot off it, and it'll give you nice menu where you can fix just about any MBR problem.
posted by Geppp at 7:20 PM on September 21, 2008