InstallShield CAB file problem

Hi all
I have some CAB files that I need to edit. Problem is, InstallShield CABs are not M$ compatible i.e. I can't open them with winzip or windows. I have tried this neat little program called i6comp, but it's not easy to master. To complicate things further, the CAB has a CRC error and i6comp won't extract the files after this error in the file.

So what I set out to do is to just swap the faulty file with a good one. (the file is nonessential for the program to run).

Any good ideas to how to proceed?

The only other file that is required to extract from an installshield .cab file is the .hdr file. i5/6comp IS the proper program to extract BUT it will do nothin for you if the .CAB is corrupted. I am unaware of any Installshield .CAB file repair programs.