>>>
>>>Sounds like it's time to accept that PkZip is depreciated.
>>
>>It has had a good life of 15 years without any problem (w.r.t pkzip 2.5)
>>
>>We have shifted to "7 zip" command line version.
>>
>>Thanks
>>
>>Rakesh
>
>Seems like a good choice, and thank you for the tip. Since PkZip also doesn't work on 64-bit Windows you would have to change sooner or later anyway.

PKZIP for DOS obviously won't work under 64-bit Windows (due to lack of 16-bit support), but PKZIP for Windows (there is a command line version available) will work just fine.

As for DOS apps -- another thing that could affect their operation is the TEMP environment variable. DOS programs will likely have problems if the TEMP directory is specified in long filename format -- changing the assignment of this environment variable to short filename format will often correct the problem. BTW, there was a version of PKZIP for DOS that was patched to make it long filename aware (never tried it -- had already switched to the Windows version of PKZIP by that time).