Sorry if i assumed that the apricorn HD was just a plain laptop HD that you wanted to use. Your comments led me to think this. Most external HD's do not have operating systems on them as they are used strictly for data. I assumed this drive was a internal drive. I have 3 external drives, ( 2 desktop and 1 laptop) that i use for saving data on computers i need to reformat and reinstall Windows on.
Just for your information heres the usual method of handling a external HD.http://www.jakeludin...hard_drive.html
The reason you cannot delete the OS on the drive is probably because it is on a primary partition. You will need to Fdisk and reformat the drive to get rid of this partition, and then format the drive as a logical drive.
Reformatting a disk prepares it to accept a new operating system. It also wipes out everything on the hard drive. That's your goal.
Past versions of Windows (through Windows ME) allow you to create a start-up disk. You'll need one to reformat your hard drive. Click Start > Settings > Control Panel. Double-click Add/Remove Programs. Click Start-up Disk. Click Create Disk.
On Windows XP, you'll need to download the disk information. Go to BootDisk.com and click "DOS — Windows 9X/NT4/2000/XP Excellent Bootdisks." Download the Windows XP Custom Install Disk and save it to a floppy.
On all systems, shut down all open programs. Restart the computer with the floppy in the A: drive. At the A: prompt, type Format: E( Drive Letter). Answer "yes" to the warning; you want to wipe out all the data.
Reformatting will keep most people out of your old files. But specialised shareware exists to reclaim files after reformatting. If you do not know who will get the computer — or you do know and you don't trust them — stronger measures are required.
Buy Software and Overwrite the Disk, Again and Again and Again
If you don't know much about computers, this might be easier. There are several programs that write gibberish to the hard drive. They promise that nobody will be able to find your files after the software is utilised.
Norton's SystemWorks includes an application called Wipe Info. OnTrack's DataEraser offers a similar feature, as does Jetico's BCWipe. There are more such applications on the Internet.
How to Format a Hard Drive With Windows XP
Right-Click on the “My Computer” icon either on your desktop or in the Start Menu and select “Manage.”
A new window titled “Computer Management” comes up. Select “Storage” from the left hand side by clicking it once, then select “Disk Management(local)” from the right side by double-clicking it.
Now in the lower part of the main frame (right side) of the window you should see a nice visual of all your hard drives. Each line is a different drive. Each box on a line (with a colored bar at the top and a size displayed in MB or GB) is a partition on the drive. Partitions are separations of space on a drive. Unless you are doing something specific that requires multiple partitions, you only want one partition per drive.
First you must delete any existing partitions on the drive you are going to format. Do this by right-clicking on the partition's box and selecting “Delete Partition...” Since you already know that you will be deleting everything on the drive, and have already backed everything up, you can safely say yes to any warning the computer presents you with.
If there are multiple partitions make sure you have saved everything off them since they might each have different drive letters (i.e. “D:” or “F:”). Then repeat the above step for each of them. If you only want to format one partition that is OK and you can continue to the next step without deleting the other partitions.
The box for the drive to be formatted should now have a black bar at the top of it and should say “Unallocated” under its size (see picture). Right click on it and select “New Partition...” The New Partition Wizard comes up.
In the New Partition Wizard click next. On the next page make sure “Primary Partition” is selected and click next. Now make the size equal to the maximum (it should already be set to it), and click next again. On the next page the computer will automatically choose the first available drive letter for the new drive. However, if you like you can choose another drive letter from the drop-down menu, and then click next.
Finally the New Partition Wizard asks if you would like to format the new partition and if so what format. Choose “NTFS” as it is faster and more secure. Leave the “Allocation unit size” as “Default.” In the “Volume label” field enter whatever name you want the drive to have. Simple is better. Avoid using spaces. Lastly, if the drive is brand new and has never been used before check the “Perform a quick format” box. If the drive has been used before leave this box unchecked. Leave the “Enable file and folder compression” box unchecked and click next. Then on the next page click finish.
The wizard will now spend a little while formatting the drive. On old or large drives this may take a while. Do not close the “Computer Management” window until it finishes. You will know it is done when the word under the size of the drive changes from “Formatting” to “Healthy” and the name and drive letter you chose for the new drive show up. After it is finished you can proceed to use your newly formatted drive.