PKZIPFIX is a recovery utility that is included with your copy of PKZIP for DOS and incorporated into PKZIP for Windows and PKZIP Command Line. It will attempt to repair a damaged .ZIP file and create a file called PKFIXED.ZIP. You can then attempt to extract from the PKFIXED.ZIP file.
To run the DOS version of PKZIPFIX, enter the directory where the damaged .ZIP file is located and type:
pkzipfix filename.zip
You can then attempt to extract from the PKFIXED.ZIP file that PKZIPFIX will create.
When PKZIP for Windows or PKZIP Command Line encounter a damaged .ZIP file, it will automatically detect the damage and will query whether PKZIPFIX is to be run. The resulting file will be called PKFIXED.ZIP. You can then attempt to extract from the PKFIXED.ZIP file.