Can I create Windows XP\'s Compressed (Zipped) Folder using Delphi?
A "zipped" folder in Windows is nothing more than a .ZIP file compressed using any standard zip library. Compressed folders are a different animal and require an NTFS disk format.
For the "Zip" file, I strongly suggest the Turbo Power Abbrevia, which is open source and works well. You might want to check this alternate site if your using Delphi 2009 as it might be a more recent copy.
If your wanting to use the compressed folders option, you will need to modify the directory flags on the directory handle. This will only impact NEW files added to that directory and will not automatically compress existing files. If you have an existing directory you are trying to compress, then rename each existing file, and load and save it back to the original name deleting the original file when complete with each one. Yozey had a good link to the MSDN documentation. Just remember that this only works with NTFS formatted disks, so you will need to add a check for that in your code.