Riddle me this one on windows boot sequence

[Lemon law]

If you run some flavor of windows, and go into almost any computer bios on the planet,
there will be, at somewhat a minimum, an option to set the first, second, and third boot devices.

In most cases, regardless if your computer has a FDD or not, it will be on the options list, a cd rom is usually choice two, and the hard disk drive is choice three and what the computer boots to if the FDD and CD rom have no media in them.

There are rare occasions when I take advantage of these boot sequences, and may want to boot my computer from either a floppy or a bootable Cd Rom. (yes I do have both a FDD and a cd rom) rather than the HDD.

In the computer in question, the bios sequence is FDD#1, CD ROM#2, HDD #3.
But in the given present need, I need to boot from the CD rom with a bootable disk loaded into the cd Rom.

But if I do not list the CD rom as boot device #1 in the bios, the computer will read the empty FDD, and then boot to windows using the HDD, totally bypassing the loaded CD rom.

But can anyone tell me why this should be so? And why does not the computer boot from the first available boot disk with media in it and do what the bios says it will do? Namely read the first boot device, if empty, go to boot device 2, if empty, boot to the HDD.

Yes its a minor annoyance to change the first boot device, but why should even be needed?

 

[nordloewelabs]

have you checked if you CD is really bootable?
if so, maybe your BIOS needs an update....
very odd.

 

[Lemon law]

Originally posted by: nordloewelabs
have you checked if you CD is really bootable?
if so, maybe your BIOS needs an update....
very odd.

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A good point, but no, still a generic question that doges the point

I could have two copies of something like memtest86, one on a bootable floppy and one on a bootable cd.

If I try to boot from a floppy disk copy of memtest86, with the floppy loaded, and the bios boot#1 device is a floppy, the computer will boot to memtest86, but if I put in a bootable CD memtest86 instead of the floppy, even if the cd is boot device #2, the computer will skip to the HDD as boot device #3. Yet if I change the bios setting to boot first to a cd and second to a floppy , that same cd will boot into memtest86, while the same floppy version of memtest86 will often be skipped even if its also loaded.

This has been my experience, not just with one computer, but on many many windows computers.

 

[Navid]

Originally posted by: Lemon law
This has been my experience, not just with one computer, but on many many windows computers.

The first device in the boot priority list that has a media in it will boot if the content is bootable or generate an error if it is not bootable. And it does not have to be the first in the list.
This has been my experience on many computers.

This has to do with the BIOS and has nothing to do with Windows or Linux or DOS or whatever.

 

[bsobel]

AFAIR some boot loaders check if they are the boot device, and if they arent and the disk is bootable pass control on to it. If the disk isnt bootable they work as normal. Its to keep some users from getting confused about their machines if they leave a cd in the drive.

 

[VirtualLarry]

Originally posted by: Navid
The first device in the boot priority list that has a media in it will boot if the content is bootable or generate an error if it is not bootable. And it does not have to be the first in the list.
This has been my experience on many computers.

Same here.

 

[VinDSL]

Originally posted by: VirtualLarry
Same here.

Dittos, but...

Isn't the error reporting dependent on whether or not you're using the 'logo screen' @ boot?

I'm too busy to POC right now...

 

[Smilin]

That behavior is completely bios and has nothing to do with Windows (or any other OS).

Your bios is making a choice to bypass the second boot device. Normally with a CDRom if the bios detects it has a MBR (el torino) it will prompt you to hit any key before actually booting to it. Are you just not hitting the key?

Also unless your bios is ancient you should be able to choose a boot device at POST rather than having to go all the way in to bios to make a permanent change. Try the F12 key.



and to answer that last question...No has the error has nothing to do with logo screen.

It does raise the question: Is your logo screen hiding the "press any key to boot from CD" message?

 

[VirtualLarry]

Originally posted by: Smilin
That behavior is completely bios and has nothing to do with Windows (or any other OS).

Your bios is making a choice to bypass the second boot device. Normally with a CDRom if the bios detects it has a MBR (el torino) it will prompt you to hit any key before actually booting to it. Are you just not hitting the key?

Also unless your bios is ancient you should be able to choose a boot device at POST rather than having to go all the way in to bios to make a permanent change. Try the F12 key.



and to answer that last question...No has the error has nothing to do with logo screen.

It does raise the question: Is your logo screen hiding the "press any key to boot from CD" message?

I'm pretty certain that the BIOS doesn't require you to press a key to boot a CD. At least I've never had to - well, except for Windows 2K/XP install CDs - where the CD's bootloader itself displays that message. (Not the BIOS)