01 January 2011

NTFS Compression versus Compressed (zipped) Folders

A New Year posting!

While playing with WMI to compress folders, I realised that NTFS compression is different from ZIP files. At the start, I wondered why my script didn't seem to create any ZIP files even though the call to SWbemObjectEx.Compress procedure was successful. Turns out that my test folder was being compressed in NTFS but I wasn't looking for it correctly; in Explorer, the folder's name is displayed in a blue colour and its Size on disk is smaller than its Size but its icon and type is the same as a regular folder. On the other hand, Compressed (zipped) folders which are just files that have been compressed, have a zipper and padlock icon. A great way to publicise a fundamental file system feature, eh?