As stated in my OP in this thread , after removing a Dual Boot I had setup when I was changing from XP to Win 7 I was left with the Windows Folder on the F Partition . This is now some time ago and I forget all the details but I think on that Dual Boot setup , I had XP on the C:\ drive and Win 7 on the F Partition. Whatever happened , after removing the Dual Boot I ended up with WIN 7 on the bootable C and a non-bootable Windows Folder also on the F Partition . I eventually forgot about the existence of this , now superfluous Windows Folder , until recently but was still using the F Partition normally. I was trying to remove this Windows Folder while still preserving the data on F but I now am realising that the simplest way to get rid of it will be by formatting that drive . I realise now that attempting to remove an OS-containing Folder is not a simple process even if it is not bootable !