>Mark,
>
>>Put the following files in the same directory as your app [or at least in a folder included in the VFP search path]. They also need to be provided with your app:
>>
>>dunzip32.dll, dzip32.dll, dz_ez32.dll, dzprog32.exe
>
> Thanks a lot for your response.
>
> Ok, I did it (put in myApp\Classes). It seems to me that now it works. I also found some other problems: if I click twice on Archived button on my form I have a DynaZip error message "Nothing to do"..., how can I avoid this?

That message is from DynaZip and is telling you that you either have no files to add to a zip file, no filespec to zip or unzip, the function you selected changes nothing [e.g., you are doing a zip refresh but all zipped files are current], etc. This could be just about any combination of the above as well.

Try modifying the sample code I gave you. If it was to unzip a file, change the name of the zip file name to a zip file you have. Also change the destination to unzip to. You can make the filespec *.* as well.