Changing Boot drive assignment.

  • Thread starter Thread starter rtrdtelco
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rtrdtelco

While setting up my new computer, WinXP Pro assigned my SATA drive as
"G" and it wasn't booting from it although XP was installed on it. I
now have it booting from the SATA and want to make it the "C". Neither
WinXP Disk Manager nor Partition Magic will allow a "Boot" drive
assignment change. Other than a clean install, is there a way to change
the boot drive assignment? I have changed all the other drives so they
are the way I want them.
Don't really want to do a clean boot.
And, as it always seems to be asked for, my system is:

WinXP Pro SE1
P4C800-E Deluxe
Intel Pentium 4 3GHz (Not overclocked yet!)
2 ea. Crucial 512MB Dimm (Dual Channel 1G)
Crucial ATI 128MB Radeon 9600 Pro Video
Plextor PX-708A DVD-RW (D)
Plextor PX-W1210A CD-RW (E)
Samsung DVD-ROM (F)
Maxtor 120G SATA (G)
WD 40G IDE (H)
Samsung 4G IDE (I) (Just because I could!)
Antec PLUSView100 case
Antec TrueBlue 480 Watt Power Supply
Five case fans

Can't wait until the next Half-Life comes out...
Thanks
Steve
 
Other than a clean install, is there a way to change
the boot drive assignment?
Click to expand...

Yes, but it may not provide the result you want. Drive assignments (in
NT) are made by entries in the registry, under:
HKEY_LOCAL_MACHINE\SYSTEM\MountedDevices

For each drive you will see an entry like (this is my G drive)

\\DosDevices\\G: REG_BINARY 53 ca 53 ca 00 cc 05 ab
01 00 00 00

Where the 53 ca 53 ca is a "signature" written in sector 0 of the hard
drive, I think around byte 140 hex. The rest is the offset from the
beginning of the drive in sectors (I think) and is big Endian as I
recall. The first partition (regardless of letter assignment) will be
at offset 7e.

So, you could edit this entry and swap the settings for G and C. There
is an excellent chance, however, that you will never boot from that
partition again, if you screw up. I don't think you will be able to
run any of the programs installed in that partition without extensive
editing of the registry. It has been some time since I tried it.

I did try doing this some time back and IIRC, gave up in defeat. There
may, however, be some utilitiy floating around to do it. I would leave
the letter assignment alone, what is the difference?

Lou
 
Already been there and done that. I already did a repair-installed XP
Pro to get SATA as boot drive. Still was "G".
Thanks anyway
 
Lee, thanks, Tim I agree with you. I don't think that this is something
that I want or really need to do. If it is going to be that difficult,
I think that I will wait until I have to a format on that drive and then
reinstall the OS. Hopefully it will then become "C". Then again, maybe
I will never need to reformat it. I can always hope so, Hmmm?
Thanks again for the replies.
Steve
 
Lou said:
Yes, but it may not provide the result you want. Drive assignments (in
NT) are made by entries in the registry, under:
HKEY_LOCAL_MACHINE\SYSTEM\MountedDevices

For each drive you will see an entry like (this is my G drive)

\\DosDevices\\G: REG_BINARY 53 ca 53 ca 00 cc 05 ab
01 00 00 00

Where the 53 ca 53 ca is a "signature" written in sector 0 of the hard
drive, I think around byte 140 hex. The rest is the offset from the
beginning of the drive in sectors (I think) and is big Endian as I
recall. The first partition (regardless of letter assignment) will be
at offset 7e.

So, you could edit this entry and swap the settings for G and C. There
is an excellent chance, however, that you will never boot from that
partition again, if you screw up. I don't think you will be able to
run any of the programs installed in that partition without extensive
editing of the registry. It has been some time since I tried it.

I did try doing this some time back and IIRC, gave up in defeat. There
may, however, be some utilitiy floating around to do it. I would leave
the letter assignment alone, what is the difference?

Lou
Click to expand...



Actually the best thing to do is delete every drive listed there, and when
you reboot it will add the drives in their order of appearance.
 
But were yr other drives disconnected?

rtrdtelco said:
Already been there and done that. I already did a repair-installed XP
Pro to get SATA as boot drive. Still was "G".
Thanks anyway
Click to expand...
 
I'm about to try what you're trying to do. I have just installed a sata
drive and copied C: over to it now I want to delete old C: and make what is
labeled I: into C: I've been checking the knowledge base at Microsoft and
other than the caution there doesn't seem to be any reason to me why
swapping drive letters can't be done as long as they contain MBRs. The SATA
drive I have is a Seagate which provides a copy program but not much info on
how to swap drive letters.

If I don't blow myself away when I try it I'll let you know what happened.
 
notritenoteri said:
I'm about to try what you're trying to do. I have just installed a sata
drive and copied C: over to it now I want to delete old C: and make what is
labeled I: into C: I've been checking the knowledge base at Microsoft and
other than the caution there doesn't seem to be any reason to me why
swapping drive letters can't be done as long as they contain MBRs. The SATA
drive I have is a Seagate which provides a copy program but not much info on
how to swap drive letters.

If I don't blow myself away when I try it I'll let you know what happened.
Click to expand...

Windows stinks for this..
You cant change it to C if something else is using C
I dont know how pc's list thing (in order of IDE then SATA or SATA then
IDE)..
but if you really wanted to do it
delete everything under HKEY_LOCAL_MACHINE\SYSTEM\MountedDevices
leave that feild there, just delete all of the data inside of it
turn pc off
remove the drives your wanting to get rid of for one..
then remove everything off of the standard IDE ports (I would just disable
in bios to avoid opening the case)
reboot the system and then it will rebuild that file and all the drive
letters will be newley assign'd
...
if your using something like alcohol 120% or ANYTHING that has mounted a
drive then DEMOUNT them first
and writable CD drives and stuff dont like the letters being changed!!!


As for how do I know deleting everything in there working

I did it!
I backed up my reg before I did it, then I done it.. it worked fine for me..
and IF your saying it might be easier to just reformat to fix your problems
then I think you should really try what I am suggesting as it really takes
you less than 5 mins
 
rstlne said:
Windows stinks for this..
You cant change it to C if something else is using C
I dont know how pc's list thing (in order of IDE then SATA or SATA then
IDE)..
but if you really wanted to do it
delete everything under HKEY_LOCAL_MACHINE\SYSTEM\MountedDevices
leave that feild there, just delete all of the data inside of it
turn pc off
remove the drives your wanting to get rid of for one..
then remove everything off of the standard IDE ports (I would just disable
in bios to avoid opening the case)
reboot the system and then it will rebuild that file and all the drive
letters will be newley assign'd
..
if your using something like alcohol 120% or ANYTHING that has mounted a
drive then DEMOUNT them first
and writable CD drives and stuff dont like the letters being changed!!!


As for how do I know deleting everything in there working

I did it!
I backed up my reg before I did it, then I done it.. it worked fine for me..
and IF your saying it might be easier to just reformat to fix your problems
then I think you should really try what I am suggesting as it really takes
you less than 5 mins
Click to expand...
Going out of town for awhile. Will take a look at this when I return
Thanks for all the info.
Steve
 
I had the same problem. When I installed, the boot drive was assigned drive
"H".
What I did was change the drive that was assigned to "C" to another letter.
Then I made a small batch file that runs the subst cmd. It looks like this:

subst c: h:\

Then added a shortcut to this batch file (actually a .cmd file) to my
Startup folder. Reboot.

You still have your boot drive assigned but now the "C" drive is mapped
to the boot drive. So you have a boot drive at "C" also (actually a mirror
of the other one).

There are still some programs that require the files to be written to the
"C"
drive upon installation. This allows you to do that.
 
The fastest way I've found to change from a PATA boot drive to a SATA
boot, or any other combo is to use an older Microsoft program called
MS-DOS! Using a DOS level floppy boot disk along with Norton Ghost you
can clone the drive, (Ghost will recognize the SATA drive without any
additional drivers) while retaining Drive letter integrity. After the
clone remove the old C:\ drive before booting up Windows and set the new
drive as first boot device in BIOS, it will be C:\. Once you've
verified the new drive is working correctly you might fdisk/format the
old drive. Some drive manufacturers have software on their web sites to
do this also, but Windows would be my last choice for this, based on my
trials (or should I say errors!)
Rob
 
Rob said:
The fastest way I've found to change from a PATA boot drive to a SATA
boot, or any other combo is to use an older Microsoft program called
MS-DOS! Using a DOS level floppy boot disk along with Norton Ghost you
can clone the drive, (Ghost will recognize the SATA drive without any
additional drivers) while retaining Drive letter integrity. After the
clone remove the old C:\ drive before booting up Windows and set the new
drive as first boot device in BIOS, it will be C:\. Once you've
verified the new drive is working correctly you might fdisk/format the
old drive. Some drive manufacturers have software on their web sites to
do this also, but Windows would be my last choice for this, based on my
trials (or should I say errors!)
Rob
Click to expand...

Doing this with XP/2000 or above would not work well.
the OS Taggs the drive in the MBR and that's how it knows what drive goes to
what letter.
you might have problems (all the op has to do is delete the reg keys and
reboot, and it will fix itself)
 
which reg keys?


rstlne said:
Doing this with XP/2000 or above would not work well.
the OS Taggs the drive in the MBR and that's how it knows what drive goes to
what letter.
you might have problems (all the op has to do is delete the reg keys and
reboot, and it will fix itself)
Click to expand...
 
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