Repiar of an external iMac USB drive after GPT from Windows 7

Repair of an external iMac USB drive after GPT from Windows 7

I have an external hard drive on my iMac with lion. The drive was formatted on this machine, and primarily used for itunes media and for time machine. I noticed that my internet was running slow throughout my house and deduced that this drive, when not plugged in, would speed up the internet significantly. I tried running virus software but had no luck.

I then tried to repair it on my Windows 7 machine. After plugging it in, I selected GPT thinking that the drive could run equally on a Windows or Mac machine.

Now I cannot read the drive on my iMac. Is there an easy fix for this?

Mount the drive and open Disk Utility. Erase and format the drive as Mac OS Journaled. (HFS +) And don't try to repair the drive with Windows if you wish it to work with your Mac. Windows will reformat the drive to NTFS which is read only from your Mac.

Although even if you use Windows to repair it you don't need to reformat it to NTFS.

When you format the drive, will that replace the partition that was there?

If you directly format it in windows I think it will do the whole drive, to partition you'll need a different software.

edhkirk said:

When you format the drive, will that replace the partition that was there?

Click to expand...

How many partitions were on the drive? If only one partition (the entire drive) then just follow the instructions I gave you above. If more than one partition exists on the drive, use Disk Utility to remove the extra partition to make one contiguous partition on the drive. After doing that, you can format it as HFS+.

Again, don't use Windows as it will re-initiate the drive as NTFS.

macmacattack said:

If you directly format it in windows I think it will do the whole drive, to partition you'll need a different software.

Click to expand...

The idea is not to format it using Windows. However, when formatting a drive for Windows use, the Disk Management utility can be used to both partition and format.

The was only one partition. I would like to keep the data if I could.

I want it to be a Mac drive.

edhkirk said:

The was only one partition. I would like to keep the data if I could.

I want it to be a Mac drive.

Click to expand...

If you format the drive, you will lose all your data. Make sure you copy the data off the drive first, preferably to another drive before formatting.

Is there any way to restore the partition?

It says "Partition map check failed because no slices were found."

edhkirk said:

It says "Partition map check failed because no slices were found."

Click to expand...

What are you using to format it again?

It was formatted with Lion. IT was then initialized with GPT on Windows 7.

When I use the AppleXsoft demo version of File Recovery, I can browse the entire volume with proper directory names and file names.

Can I repair this volume "in place"?

Or do they all have top be copied (using this utility) to another volume?