Booting windows on multi-partition USB flash drive

[galapogos]

Hi,

I have a USB flash drive that has multiple partitions, and the 1st partition is actually an emulated CD-ROM partition. Is it possible to instruct a PC BIOS to boot to specific partitions on the drive, if the different partitions contain different OS installations?

[cdob]

A average BIOS dosn't support this.

Some BIOS boot CD-ROM partition only.

Some BIOS boot data MBR only, no specific partition select.

Some BIOS allow CD-ROM or data MBR, no specific partition to select.

[jaclaz]

I have the usual feeling that there is a mix up between WHAT you want/need to do and the HOW to do it.

You don't normally have a USB stick with multiple partitions of which one is an emulated CD-ROM partition.

It is more likely that you have a U3 or similar USB stick.

The controllers on these sticks can be set to have TWO LUN's (i.e. TWO devices) the first "CD-like" and the second "HD-like".

If this is the case, you don't have a "partition" that emulates a CD-ROM , you have a device that emulates a CD-ROM and all the other partitions are on the second device, which emulates a hard disk.

Usually on U3 devices the CD-ROM like LUN "prevails", so what one normally does is to use a bootable .iso in it containing a multibootloader or bootmanager, like grub4dos, then this latter once booted allows to choose which of the partitions on the "other" LUN or device .

Since it costs nothing to have the same bootmanager on the Active (Primary) partition of the "other" LUN or device,even if the second device is "chosen" by BIOS it won't make any difference and you will still be able to boot the whatever you want to boot.

If you are positive that you are NOT having the setup described above, please detail HOW you managed to get that USB stick partitioned/formatted as you initially described.

jaclaz

Edited March 28, 2011 by jaclaz