Serial means a unique number or code which identifies the license of the software as being valid. All retail software uses a serial number or key of some form. A serial number can also be referred to as an Activation Code or CD Key. When you search for Ipartition Key Serial, you may sometimes find the word 'serial' in the results.

I have a 250G external HD on which I have 3 partitions. One is a Time Machine backup and the others are for 'manual' backup. I am running 10.6.4 on an iMac. I just realized that I have the ext HD partitioned using an Apple Partition Map instead of GUID. Plantronics ml20 proshivka. This goes back to my using the HD for my old machine and using SuperDuper to back up. I understand that I really should have the ext HD partitioned with GUID. Is that correct?

Can I change the partition scheme without erasing the ext HD? Assuming I cannot, what are your comments about copying the contents of the ext HD to my iMac (plenty of room), properly reformatting and repartitioning the ext HD, and then copying the backup files back to the ext HD?

Will Time Machine recognize the backup files in their 'new' location? Hi David: If you are only needing the external for Mac OS X extended file system (hfs+) partitions, then reformatting to GUID (GPT) is a waste of time. GPT does not change anything about the HFS+ file system. It only allows other file systems such as MSDOS to be installed, any HFS file systems present on a GPT disk are nothing more than a Apple APM format with a GPT wrapper. If you need to make the APM formatted drive bootable, you won't be able to use the install disks to do it though. Install disks require a GPT format. You can however, use super duper or CCC to place a clone on the APM disk, and it will boot.

In other words, you can still boot from an APM disk, you just can't use the install dvd to install the OS on it. There is a third party utility that can do anything and everything you want done without reformatting or repartitioning. It's not a free utility, but here is a link to it: You would still be wise to backup before using iPartition though.

Kj Message was edited by: KJK555. You are correct, although it is not essential except under certain circumstances. You cannot change the partition map scheme without repartitioning the drive which will result in the loss of everything on the drive. You will need to copy the data to another drive preferably not your startup volume. Backing up from your startup volume to the startup volume is not backing up. For advice on using TM: See for help with TM problems.

Also you can select Mac Help from the Finder's Help menu and search for 'time machine' to locate articles on how to use TM. You are correct, although it is not essential except under certain circumstances. You cannot change the partition map scheme without repartitioning the drive which will result in the loss of everything on the drive. You will need to copy the data to another drive preferably not your startup volume. Backing up from your startup volume to the startup volume is not backing up.

For advice on using TM: See for help with TM problems. Also you can select Mac Help from the Finder's Help menu and search for 'time machine' to locate articles on how to use TM. Were you to do that then I would first turn off TM until you finish reformatting the external drive.