Unmark a disk as Active

[David Walker]

As part of installing a new Windows XP Pro on another disk drive, in
preparation for removing the old 13 GB C-drive from the computer, I had
a step where it would have been very convenient to un-mark the old C
drive as "Active".

I know the computer boots off the first disk in the chain that it finds
marked Active. I made the new, eventually-to-be-the first disk in the
system active, but I didn't want to recable things until I was sure I
didn't need anything off the old 13 GB drive, so I wanted to "unmark"
the primary master disk active.

Is there any way to unmark a disk active? Do I have to run a hex editor
on the partition table? shouldn't there be an easy way? Once you mark
a disk Active, is there any way with standard tools like FDisk to
reverse that (does it required deleting all partitions, for example?)

Thanks. It's hard to search for "mark disk not active" in Google.

David Walker

 

[Guest]

What is your end goal?

there is no need to un-mark active partition.
Especially if you're removing it from computer.

Are you going to recable now and have 13 gig as slave?

run fdisk and remove active status, if you must. i don't you will be able to
boot to this drive in this state.

 

[Jim]

BootIt NG will do it through its partition manager, simple operation.

Jim

 

[David Walker]

What is your end goal?

there is no need to un-mark active partition.
Especially if you're removing it from computer.

Are you going to recable now and have 13 gig as slave?

run fdisk and remove active status, if you must. i don't you will be
able to boot to this drive in this state.

I didn't want to physically remove the first disk *until* after I was
100% sure that I had all the data off it and didn't need it any more.

In the meantime, I wanted to make the third disk active, because that
was eventually going to be the first disk (but not until I pulled the 13
GB disk that was currently primary master) and have it be the boot disk,
while leaving the first and second disks in there for the time being.

The 13 GB was going away completely... Eventually. But first I wanted
to make sure my OS would boot. If things failed, I would re-mark the 13
GB active and reboot!

As far as I remember, FDisk will SET active status on a disk but won't
REMOVE it from a disk. Or does it remove ACtive from all other disks
when you remove one?

Disk Administrator will happily let you mark all your disks active. My
second disk in the mix had been marked active at some point in the past
but I didn't want it to be the boot disk -- I wanted the disk that was
temporarily third in the order to be the boot disk.

I hope all that makes sense; do you see why I wanted to unmark the 13 GB
(first disk) and the second disk active?

Anyway, as the other commenter said, BootIt NG will do the trick. But
it costs money, and I was looking for something preferably free...
although I do buy software when it does a good job (like SyncBack SE).

David

 

[David Walker]

And why isn't the un-marking of a disk active, documented anywhere; it's
convenient for temporary situations while in the middle of rebuilding a
system.

 

[Jim]

I didn't want to physically remove the first disk *until* after I was
100% sure that I had all the data off it and didn't need it any more.

In the meantime, I wanted to make the third disk active, because that
was eventually going to be the first disk (but not until I pulled the 13
GB disk that was currently primary master) and have it be the boot disk,
while leaving the first and second disks in there for the time being.

The 13 GB was going away completely... Eventually. But first I wanted
to make sure my OS would boot. If things failed, I would re-mark the 13
GB active and reboot!

As far as I remember, FDisk will SET active status on a disk but won't
REMOVE it from a disk. Or does it remove ACtive from all other disks
when you remove one?

Disk Administrator will happily let you mark all your disks active. My
second disk in the mix had been marked active at some point in the past
but I didn't want it to be the boot disk -- I wanted the disk that was
temporarily third in the order to be the boot disk.

I hope all that makes sense; do you see why I wanted to unmark the 13 GB
(first disk) and the second disk active?

Anyway, as the other commenter said, BootIt NG will do the trick. But
it costs money, and I was looking for something preferably free...

Actually, it doesn't, not for most partition managent functions. Simply
boot the floppy/CD, and when the Welcome screen appears, hit Cancel. Follow
the prompts until you reach the BootIt NG desktop and hit the partition
manager icon. From there you can perform all the partition management
functions you need, even create backup images.

Jim