Help with mobile/removable drive, please

[Pete]

At any one time, I have 3 PCs, all running WinXP.  PCs 1 & 2 are always in the same location and PC3 is normally elsewhere.  I move data to/from PC3 via a "mobile" drive (a normal IDE HDD) with a rack in each of those PCs.

I have recently had to replace PC3.  I have sometimes replaced PC2 and PC3 over the years but have never hit the following problem before!

On PC3:  BIOS recognises the mobile drive.  Windows Explorer does not show it.  In Disk Management, I see Disk 1.  It does not have a drive letter allocated and is shown as "unallocated".

I have created a new partition and allocated drive letter D.  The drive then appears in the Explorer and I can successfully copy data to it.

I then shut down PC3, transfer the mobile drive to PC2 and start that one up.  The drive appears in the Explorer and I can see the data on it.  I can open any of the files.  I can delete all the files and copy new ones onto the mobile.  So far so good!

Then I shut down PC2, put the mobile back into PC3 and start it up again.  Now I'm back to square one with the drive showing in Disk Management as "unallocated".

All that means that I can now transfer data in only one direction.

I don't believe there's anything wrong with the drive itself as I have two drives in mobile cases and the above happens with both of them.  As this has never happened when I have previously had to renew PC2 or PC3, I'm lost!

I looked on CH before posting this.  I found the suggestion to initialise the drive via right-clicking in Disk Management but when I right-click, I don't see the initialise option (only New Partition, Properties and Help).  Maybe that means that the drive is already initialised.

By the way:  The mobile drive is configured as a slave and that's the same in both PCs, of course.

I would be very grateful for any suggestions!

Pete

[DaveLembke]

Is your mobile drive larger than 137GB? If so is your IDE controller on PC3 the system having issues a 48 bit IDE HD controller which supports drives larger than 137GB or is it a 28-bit which caps at 137GB?

Your Bios will be happy with a 250GB drive on an 28-bit controller, but it will say unallocated because it can not address the 48-bit partition structure, and so it will address it as 137GB and that is why its not reading the partiton as being there, and should show max size of 137 GB

 If this system is an older system it is likely a 28-bit controller and this is the problem. Way to fix this is to install a new 48-bit IDE HD controller in that system to be able to address a 48-bit IDE drive.

[Pete]

Is your mobile drive larger than 137GB? If so is your IDE controller on PC3 the system having issues a 48 bit IDE HD controller which supports drives larger than 137GB or is it a 28-bit which caps at 137GB?

Your Bios will be happy with a 250GB drive on an 28-bit controller, but it will say unallocated because it can not address the 48-bit partition structure, and so it will address it as 137GB and that is why its not reading the partiton as being there, and should show max size of 137 GB

 If this system is an older system it is likely a 28-bit controller and this is the problem. Way to fix this is to install a new 48-bit IDE HD controller in that system to be able to address a 48-bit IDE drive.

Dave,

Many thanks for your response.

No, the larger of the two mobile drives is only 13GB so it doesn't sound as if that's the problem.

Pete

[patio]

A Reach...but try it on machine C

[Pete]

A Reach...but try it on machine C

Patio,

Thanks also to you for your response.

I followed the link and tried to follow the instructions.  I started up in safe mode but don't see the "Security" tab for my mobile drive (drive D) when I right-click and go to Properties.  I am definitely logged on as an admiadministrator (I do see that tab for Drive C).

Some more info to all:

1)  Tried to include all relevant info in my original post but forgot to mention that my version of WinXP is the Home Edition with SP3.

2)  Have since discovered that if I do the following sequence...

a) Put the mobile in PC2 and "repair" it.
b) Put it in PC3 (getting the usual "unallocated" status, of course).
c) Put it back in PC2 without having read or written anything.

...PC2 then says it's "unallocated"!!!  (I've just lost all my back-ups that way but they can soon be re-created.)

Grateful for any more suggestions from anyone.

Pete