I was swapping around some drive letters using the disk management program in XP and fumble fingered my way to setting one of my 300GB movie drives to active. Is there a way for me to reset the drive back to a non-active state without having to copy all of the data to another drive and then delete the partition on this drive? Of course, I don't want to lose the data. As I remember the earlier versions of partition magic (before NTFS) let you do this but the newer versions do not.

Thanks!

This MS knowledge base might help KB315261

Thanks gbeer the answer wasn't there but it was a good read.

Yeah, well I wasn't quite sure what you meant by Active. That seemed to fit.

What I did was I set one of the movies drives to "Active". This means that I have flagged it as the drive that the system should boot from. There is only supposed to be one drive in a system that is set to active. On a Windows box it is generally the "C" drive. The "Active" drive is also suppose to be located as the master of the primary IDE channel. I would like to remove the "Active" flag from the movie drive I set it on without losing the data. What I did is actually not causing any problems as the system sees the correct drive first and boots from it. I would still like to remove the flag from the other drive just to make it correct. I think it is interesting that so many applications allow you to set it but to unset it is problematic. Seems kind of goofy. I can just copy the data to another drive. I'm kind of on a quest to figure out a way to reset this flag though!

Oh. That kind of active.

Grab a Linux boot disk, boot off of it, then run the "fdisk" command against the appropriate drive. Assuming it's the second IDE drive in your system, probably "/dev/hdb". Type "p" to show the current partition table. There should be an asterisk in the "boot" column on the partition you marked active. Type "a"; it'll ask you for a partition number. Enter the partition you want to toggle the flag on. Type "p" again to verify that it's gone. Then type "w" to write it out and exit. Reboot.

Wow! Thanks Bitt! I can do this on a NTFS drive via Linux?

It's not universal. It's specific to the IBM PC platform. I imagine it was invented by IBM back in the early 80s, but I could be wrong. Other architectures use different methods.

Basically, the IBM PC partition table is defined to be on the first sector on the hard disk as part of the MBR (Master Boot Record) and it consists of four 16-byte records, each defining a partition. There can be no more than four primary partitions in this architecture. There are a number of ways "sub-partitions" can be defined, but they are all defined within the space of the primary partition itself.

Wikipedia has an entry on the IBM MBR and partition table scheme.