dual boot revert and dual boot hardware

[peter_ming]

hi guys,

I just have two simple questions:
1. how do we revert from dual boot to single boot (aka. deleting the dual boot once the second OS is uninstalled)?
2. is it possible and okay to dual boot via hardware (from bios set up we chose which hard drive will be the first boot)? I want to install XP and Vista/W7 on two separate HDs without the dual boot features, so that when something happens to the first installed OS, i can still boot from the next OS.

Any links to previous postings about this which I might miss will be appreciated.

Thanks a lot!
Peter

 

[KSoD]

1. Which OS's are installed and which one are your removing? With that what is the location of the install on the hard drive? First partition, 2nd partition or what?

This is very important information as it will allow for direct advice on what to do and what can be done. I know that in the Win7 thread i have given advice to Trotter on how to accomplish this when he removed XP from his system and installed Win7. I dont know the exact page or post number but it is there.

2. Yes this is possible but will be tough to accomplish. For the OS's on separate drives just disconnect the drive that is not going to be used. That will stop the boot loader from creating multiple entries. But when yo go to add 2 OS's to a single drive on separate partitions it will be much harder to accomplish as Win7 (or vista which ever is installed last) will detect the previous OS and give a boot selector screen.

You would then hit F12 to select which OS to boot to.

 

[peter_ming]

hi mak,

you have come very fast to my rescue as always, thanks!

1. First OS is XP on first HD first partition, second OS is W7 on second HD first partition. I'll try to look up at W7 thread later on.

2. I'll install second OS on separate HD, so no chance of it being mixed up (?). And must I unplug the connector? How about moving up/down via bios for the first HD to boot from, will the boot loader comply?

Awaiting for your fast help with much gratitude.

 

[KSoD]

1. Alright if you wish to remove XP it will be tricky. As you will have to mess with some settings in Win7 first to get it to boot. It would require you to set the Win7 partition as the system active drive. From there you would have to make sure that the BCD (Windows boot loader for Vista/Win7) is located on the drive so that it can boot.

This is a tricky procedure and while can be accomplished will take some work and is very trial and error based.

2. From what i was reading you were going to install XP on 1 HDD and then Vista & Win7 to the 2nd HDD. Is that correct? If so then the 2nd hard drive you would get the boot menu. As the install of the latter OS would detect the previously installed Os and setup a boot selector screen.

Now if you are just going with 2 HDD's and 2 OS's, 1 on each drive then it can be accomplished. You would have to turn off the drive in the BIOS if it is SATA or physically remove the power connector to the drive for IDE. Just moving it down the boot order will not do anything as the install of the 2nd OS will still detect the drive (Which you would see at the Drive install selector screen) and as such create a boot selector menu. It would require that the drive be disconnected either by the BIOS or by not having power to stop this and allowing for the use of F12.

I know that some will say that it still can be done if you use F12 first, but this method i am saying is a full proof way to prevent the boot loaders from ever detecting each other and ensure that you will not have a selector screen. If you just let the PC boot without hitting F12 it would to directly to the Drive that is set to be the first boot drive.

 

[peter_ming]

mak:

1. I want to remove 2nd installed OS, not XP. Will a simple delete on partition will prevent the bootloader to recognizing two OS?

2. What if I disconnect cable of 1st OS HD before installation, then install 2nd OS HD from scratch? When both HDs are connected and first boot device is chosen from BIOS, will the bootloader still screen both OS, or will it even freezes from confusion? My PC bios once got mixed up and could not boot. Two frantic hours later I just realized that it was only a matter of first boot device selection. So the 2nd OS cannot boot without the 1st OS present, or the 1st OS HD being the 1st boot device. Perhaps this is much like your # 1 answer above.

 

[KSoD]

Alright clarify for me what you are trying to do. What is the 2nd installed OS? Win7? Vista? XP? Linux? Just saying 2nd installed OS doesnt mean anything as it can be any OS out there which was installed 2nd. I dont know which order you installed the OS's in so just saying the 2nd installed one gets us no where.

Plus if you only have XP/Win7 and you are trying to remove Win7 but still keep the BIOS Boot Method my next question would be why? If you remove 1 of 2 OS's installed then there is no need for the BIOS boot method or a Boot Selector screen. It would just go from the BIOS splash screen right to your XP install. No extra steps needed.

So clarify for me what you have and what you want to do. I know you have XP on your 1st HDD 1st partition. Win7 on the 2nd HDD 1st partition.

Which one do you want to keep which one do you want to remove? Are you going to install Vista/Win7 again or just stick with a single boot?

 

[peter_ming]

sorry to confuse you mak:

XP is my primary install on 1st HD, Win7/Vista is the secondary install on 2nd HD, all are placed in the first partition of both HDs. I want to retain XP, delete Win7/Vista. Will a simple partition delete be enough and dual boot loader will be bypassed?

Thanks again for the help.

 

[KSoD]

Okay first to clarify, Vista and Win7 are different. I just use the Vista/Win7 reference cause it makes it simplier for people since they use the same boot loader.

Now since you are just getting rid of Win7 and going strictly with XP you can use GParted to format the partition that Win7 is on. After that you can insert the XP Disk, go to the Recovery Console and use these 2 commands:

fixboot
fixmbr

In that order. Fixboot will set the XP boot up correctly, not that it should be affected at all since Vista/Win7 (Again just a reference since they both use the BCD loader) doesnt use boot.ini to boot the system like XP does. The fixmbr command will get rid of any reference to the BCD and allow for XP to boot directly.

This will get rid of Win7 and have your system boot straight to XP. Right after the BIOS Splash Screen you will see the familiar XP loading screen, or a custom boot screen if you have one of those installed.

Everything else wont be needed as this is a much simplier fix than what it was made out to be. Leave XP as the first drive and first on the boot order.

 

[peter_ming]

ah, now everything is clear as sky, thanks a lot mak!

yes, of course Win7 and Vista are two different OS, but my guess is that they use the same boot loader so treatment to them should not be any different.

Still got a lot to tweak and twist with my XP, hope it's gonna be a fun road to travel

 

[peter_ming]

@ mak: I reinstalled Vista (the tweaks I did on first installation was a mess :embaressed, and now the bootloader is acting crazy right before it shows the dual boot option. It actually doesn't affect the booting process, but it annoys me by showing lines of texts, something like 'bootmngr is missing something something... (the screen blips so fast I can't get the details). Now will fixboot and fixmbr work on this condition? I'm worried that fixing it will delete the dual boot option and I must reinstall Vista yet again.