Failing to boot boot-utility from external hdd

joe111 · 31 May 2012

Hi Guys

The last time I re-installed Win7, I created a 5GB partition on my external hdd, marked it as active and then extracted a downloaded ISO of Win7 to the partition. Using the boot manager, I could select boot from USB and everything worked fine. Complete success.

I thought that it would be useful to replace the extracted win7 ISO with an extracted ISO of a boot utility disk. I have tried several, but none are working. Two, show no message at all and the system resorts to booting from the internal hdd, the third gives a "BOOTMGR is missing" error.

Am I doing something wrong or have I downloaded boot utility disks that don't work.

If it's the former, what have I missed? If it's the latter, where can I find a reliable boot disk with good utilities that will work from an external hdd.

Thanks in advance.

Duzzy · 31 May 2012

Some boot disk use Windows Boot Loader (Win Vista,7,8) or NTLDR (WinXP) but some use GRUB4DOS and some use IsoLinux or SysLinux. Depending on what boot loader they use determines which boot sector the drive will need. A couple can use one or another.

If the boot disk contains a file called

BOOTMGR then it uses Windows Boot Loader (Win Vista,7,8)
NTLDR then it's WinXP's
GRLDR or menu.lst then it's GRUB4DOS

I am not familiar with IsoLinux or SysLinux but I think there will be at least isolinux.cfg or syslinux.cfg.

Determine the bootloader used and I can help with installing the correct boot sector as long as it's not IsoLinux or SysLinux.

joe111 · 31 May 2012

Thanks Duzzy

There is a grldr file, and a folder on the root called boot, that has both a grub4dos and syslinux folders. Does that mean the image has all that is required to boot?

Duzzy · 31 May 2012

joe111 said:

Does that mean the image has all that is required to boot?

It should except you need to install the boot sector to the drive. I find it pain trying to find the correct downloads for GRUB. I downloaded mine from Downloads - grub4dos-chenall - grub4dos - Google Project Hosting

I'm not sure what version mine is at the moment but grab the latest Featured version not TestOnly, should be grub4dos-0.4.5c-2012-05-22.7z.

I got the installer from Hiren's BootCD From USB Flash Drive (Pen Drive) » www.hiren.info. Download grub4dos.zip under Step 3.

Extract them both then copy all the files from the first download into the folder of the second one. The first one isn't really necessary but it'll give you the latest version.

Follow Step 3 to install it to the drive by following the green number points in the image. Make sure you select the correct drive, confirm this via the size and/or Disk Management. This should be all you need to do presuming the drive/partition is set as Active and your copied the files to the drive.

This should work with a drive formatted as NTFS but you may have to use FAT32 if it does not work.

joe111 · 31 May 2012

Thanks again, late here now, I'll try tomorrow and report back.

gregrocker · 31 May 2012

You can also write Hirens and many other boot disks to USB using Universal USB Installer however you need to format the HD using the tool first which is but one reason most use a flash stick, or CD.

joe111 · 01 Jun 2012

Hi Guys

I think this is solved enough to finish. I wasn't quite able to use any ISO I wanted but I have a working "rescue partition" which is good enough.

Duzzy, the usb installer that you linked to would only allow me to select the entire hdd, and not just the partition I had set aside. I assumed that if I proceeded I would have formatted my backup partition too (on the same external hard disk).

So I then tried the universal usb installer that gregrocker suggested. First I tried selecting one of the last two options (old syslinux) and then chose a boot utility ISO I had already downloaded. Trying to boot this led to the first "SYSLINUX..." line showing up but then no further activity.

I tried again with the universal installer but choosing a supported option from the list (Trinity Rescue Disk) and this booted fine, so up and running with this. Thank you very much for your help, both of you.

DIRECTIONS for anyone trying to do this. It's pretty simple. Download the Universal USB Installer and follow the instructions.

To create a bootable rescue partition on an external hdd.

1. Create the partition of suitable size (5GB for example) on your external hdd. Use any method you like such as diskparted or diskmgmt.msc in Win7.
2. Download Universal USB Installer
3. Select one of the supported rescue disks of your choice and check the box to download it.
4. Browse to the downloaded file and check the "Show all drives" box.
5. Select the partition you previously created. MAKE SURE YOU HAVE CHOSEN THE CORRECT DRIVE.
6. Check the "Format drive" box and click create.

You're done.

Duzzy · 01 Jun 2012

Good to here it's working.

joe111 said:

Duzzy, the usb installer that you linked to would only allow me to select the entire hdd, and not just the partition I had set aside. I assumed that if I proceeded I would have formatted my backup partition too (on the same external hard disk).

Just to clarify you only needed the Grub4Dos zip file which had the grubinst_gui.exe then run that and follow the instructions in step 3, no need to format at all.

The grubinst_gui.exe only writes the GRUB bootsector to the drive and under Step 3, point 3 (highlighted dot next to Part List) you select whole disk because the drive can only have one bootsector installed at any time (I believe) which looks on the active partition for the boot loader.

GRUB bootsector looks for the GRLDR or GRLDR.mbr file, Windows Vista,7,8 bootsector looks for the BOOTMGR file.

gregrocker · 01 Jun 2012

Remember that you'll also need the Win7 DVD System Recovery Options or System Repair Disk to repair Win7 if it ever becomes unbootable in the first place.

Since you need that anyway you can also rescue your files using Copy & Paste - in Windows Recovery Console.

May I ask what it is about a rescue disk that makes you prefer it? It won't repair Win7.