View Full Version : Bootable USB drive and fdisk /mbr

28-09-2004, 06:23 PM
I just got myself a small pc i want to use as a server and am in the middle of setting it up. The only drive I have in it is the HDD, I have no floppy or cd player, so I got myself a USB flash stick and made it bootable.

However, when it boots my new system the flash stick shows up as c: and the primary drive under fdisk, and I need to clean the master boot record of the hdd in the system (which shows up as the secondary under fdisk). I know that "fdisk /mbr" will do this, but only when the mbr to be cleared is on the primary drive.

Unfortunately this will clear the mbr of my USB stick, not the hdd.

Is there any way to clear the mbr of the secondary drive, either with fdisk or another app?

(I do not want to have to dissasemble any of my other pc's to fix this as i envisage doing this often, to both my machine and others, where floppy or cdrom drives are not available).


28-09-2004, 06:39 PM
email me and i will send you a small program that will kill the MBR of any disk you want.

robsonde at hotmail

28-09-2004, 09:39 PM
boot off the usb drive try C:\ type "sys d:" (where d is the drive letter of your hard drive) take out the usb drive and boot.

Graham L
29-09-2004, 04:39 PM
FDISK should be able to"change disk" to the harddisk, then make it "active". I was confused by the references to"clear"ing the MBR... FDISK/MBR restores the MBR part of the default disk, and makes it bootable. It doesn't "clear" it. It's the "ACTIVE" flag in the partition table which decides which disk boots. It might be all that needs to be fixed.

SYS D: might do the same, but it will alsocopy "system" files from the boot disk. This might not always be what is wanted.;-)

29-09-2004, 06:25 PM
Sorry, i probably should have said I had a version of mandrake on the drive earlier, but had formatted it and used it as a data disk in the meantime. When I tried to return it to service as a boot drive, the remnants of Lilo where causing me to see "L 99 99 99..." when the drive started to boot.

I read on the web this is a known issue and to fix it simply clear/restore the mbr. however, with my setup the way I would normally do it was not possible.

I got sent an app that cleared lilo out, but I am still unable to change the active flag of the system hdd while booted from the USB, as fdisk will only change the active flag of the 1st disk, and the USB device shows up as disk 1, and the systems hdd as disk 2. Some help with this would be appreciated - maybe there is another/better app to do DOS partitioning etc??