XceedZipLib.XceedZip zip = new XceedZipLib.XceedZipClass();
zip.License( @"your license key" );
// Specify which files will be added to be unzipped.
// Setting this property to an empty string will
// extract all the files from the zip file
zip.FilesToProcess = string.Empty;
// Specify the name and location of the zip file.
zip.ZipFilename = @"d:\fonts.zip";
// Specify the location where the files are to be unzipped.
zip.UnzipToFolder = @"c:\test";
// Unzip the files
XceedZipLib.xcdError result = zip.Unzip();
MessageBox.Show( zip.GetErrorDescription( XceedZipLib.xcdValueType.xvtError, ( int )result ) );