WinZip does not let you create or update files in these formats, but other features (Extract, View, CheckOut) all work.
在http://www.winzip.com/internet.htm上有对TGZ的解释。
Unlike ZIP, TAR, LZH, ARJ, and ARC files, gzip files contain only ONE file.
Unlike ZIP, LZH, ARJ, and ARC files, TAR files are NEVER compressed.
Since TAR files are often distributed in Z format (with extensions like .TAZ, .TGZ, and TAR.Z), WinZip treats Z files containing a TAR file as a special case: WinZip offers to decompress and open the TAR file.