Formatting an Ex-Drobo HDD for ordinary use

I have now upgraded the drives in my Mk1 Drobo with larger drives. the old (500GB) drives are still good so I want to reformat them for use inside my computer (Windows XP). I tried formatting one to NTFS but the computer does not see it. Any suggestions on how to get the drives back to ms-dos type format?

Do you see these drives in “My Computer / (right click) / Manage / Disk Management”? You mentioned you’ve tried formatting one to NTFS - so, you were able to format it but the OS ignores the newly formatted drive or you don’t see the physical drives in the OS at all?

I can see the drive in ‘Disk Management’ and can assign it a drive letter, but not seen in the ‘My Computer’ window nor Disk Defragmenter, ‘Send to’ menu etc.

thats very strange, but it is not related to your drobo having used the disk formerly - once they are ntfs formatted they will retain none of the drobo info.

if you format it to fat32 and assign it a drive letter - doest it then show up in explorer?

In Disk Manager is there an option to initialize the drive?

This option should create the partition table. Once done you can create an format a new NTFS partition.