Urgent, I need to repurpose a GUID drive for XP

[herojig]

Hi all, I have a small portable USB drive that I was using on a mac/intel, but I have to use it on an XP laptop today. I don't have access to a mac to reformat the drive. Disk Director sees it, but the partition is read only. What to do? thanks!

[MudCrab]

Do you need to keep the data currently on the drive?

Can you delete the existing partition with DD and create a new partition in the unallocated space?

Or will DD not do any operations on the drive because it's Read-only? (Can't delete partition, etc.)

[herojig]

-{ Quote: "Do you need to keep the data currently on the drive?

Can you delete the existing partition with DD and create a new partition in the unallocated space?

Or will DD not do any operations on the drive because it's Read-only? (Can't delete partition, etc.)" }-

mudd, thanks for the quick reply:
no, i dont need the data
In DD, I can see the partition but the only option is to edit the partition table, i can't use any of the other normal DD functions...arg!

i do get an error message on DD open when the drive is attached, says it cant access one of the drives. There is nothing special about this drive except that it was formatted using a mac/intel in leopard, using a guid partition map. i need a tool that reverses that in XP...

[MudCrab]

Have you tried booting to the DD CD in both the Full and Safe Mode versions?
Perhaps one of them will allow changes.

Another option (with DD running in "Manual" mode) would be to right-click on the "Disk #" for the drive and then Advanced->Edit to open the Disk Editor on Sector 0 (the MBR). Use the Disk Editor to Fill on the sector with zeros. Highlight (select) the entire first sector (Sector 0) using the mouse and then select Edit->Fill and pick "0" as the value. After you apply (save) the changes, it will "wipe" the MBR from the drive including any partition info. If a GUID setup is different, you may need (or want to) "wipe" the next few sectors too.

Once the MBR (and any following sectors, if necessary) are wiped, hopefully you should be able to create a new partition.

I'm calling it a night. I hope you have success.

[herojig]

-{ Quote: "Have you tried booting to the DD CD in both the Full and Safe Mode versions?
Perhaps one of them will allow changes.

Another option (with DD running in "Manual" mode) would be to right-click on the "Disk #" for the drive and then Advanced->Edit to open the Disk Editor on Sector 0 (the MBR). Use the Disk Editor to Fill on the sector with zeros. Highlight (select) the entire first sector (Sector 0) using the mouse and then select Edit->Fill and pick "0" as the value. After you apply (save) the changes, it will "wipe" the MBR from the drive including any partition info. If a GUID setup is different, you may need (or want to) "wipe" the next few sectors too.

Once the MBR (and any following sectors, if necessary) are wiped, hopefully you should be able to create a new partition.

I'm calling it a night. I hope you have success." }-

Thanks for ur help! But filling the first two with zeros does not wipe out the GUID demarcation. Does it hurt to zero the entire drive? I dont want to destroy thing unless absolutely necessary:)

ps. Same behavior in safe, full, and XP modes... surely someone has thought of this as the mac intel format has been out for awhile now...
Also, in windows XP Computer management applet, it shows the drive as "Healthy (GPT Protective Partition)" whatever that means...

[herojig]

SOLUTION FOUND:
http://tomch.com/wp/?p=50
gotta love google, once ya know what to search for, did search on GPT partition...found that procedure...