Hi, I make any tests with this very good component and don't found problem except a test with a very big file to compress. 1) The file to compress is about ~ 1.6Gb. (1.600.000.000 Bytes) 2) I used for the test the program DEMO1 for Cbuilder (the Cbuider version used is 5.0 + service pack 1) but the same result I achieved with the freeware program QuickZip (ver 2.15) 3) for this test libraries version (ZIlDLL.dll and UnzipDll.dll) is 1.60. 4) Both the program ( DEMO1 and QuickZip) build the compress file but both, put a message "Invalid Zip file". Question: There are any limitations on file size to compress? Possible Bug? Thanks on advanced for any kind of answer Luigi Robbiati