Ok, I think (although seldom) that I see the trouble. Is Winzip actually trying to just extract the CAB from the overall zip, or is it trying to extract not only the main zip file, but ALSO the contents of the CAB file? If it's trying to actually extract the CAB file's contents, then it is going to be a problem, for Winzip.
It would be my advice, but that's all it is, is advice, to download and install the latest version of 7zip, either 32bit, or 64bit, whatever your current system is, and use that instead of Winzip. Just open the zip file by double clicking it, highlight the main folder, which should be the only thing visible when you open up the zip file with 7zip, and tell it to extract. It will place it where you tell it to, in this case, \fsx\Simobjects\Airplanes, wherever you FSX resides. After all, it IS a 7zip created file, and that program, to me, is much better for this than Winzip is. 4 clicks, two to open the zip file, one to highlight the folder, one to Extract. The hardest part (and this
isn't really hard, I am being facetious) is telling 7Zip where to stick it, so to speak
Oh, you may have set the file's association to 7Zip, although I THINK when you install 7Zip, if you do, it will automatically change the associations of any 7Zip created file to the proper 7Zip program. If you permit, it will actually, I believe, change most of the compressed file's associations to 7Zip. I use it for CAB files, along with most everything else. But that's just me.
Also, if you have FSX parked in C:\Program FIles (x86), make sure you have full Administrator priveliges set for that folder at least. AND make sure you always run FSX, Winzip, and 7Zip (if you install it) as Admin.
Let me know the result, and if this doesn't fix your trouble, let me know, and we will go from there, ok? I hope this solves your troubles!
Pat☺