To easily move HDDs between Windows and Mac, use ExFat instead of NTFS. It's supported by both OSs and can use large files (unlike FAT32).
Installing the ProRes codec (read only) on Windows is trivial. Install Quicktime and you are done. However, lots ofpeople here will pour scorn on using *anything* encoded in a Quicktime wrapper because it's (currently) a 32 bit platform so is perhaps not running as fast as the native 64 bit codecs.
Personally, I use ProRes quite happily on both Windows and Mac. Another alternative is Avid's DNxHD (free download for both Mac & Windows).
< waiting for Jim and others to jump in here for the usuall go around with what codec is the best >
NTFS will work fine, but you may need special software to format and write such.
The XDCAM EX files should work fine as is, if they were copied directly from the solid state card to the hard drive using Finder, with the full original folder structure intact and without having been processed at all by FCP.
The ProRes files can be worked with under Windows, but the client will somehow have to get the codec onto their system. I don't work with that media, so I don't know exactly how that's done. If the client doesn't want to do what's needed to make ProRes work, then I'd ask where did the ProRes files come from? Are they sourced from a camera and converted? Or from somewhere else?
Great. I have Tuxera NTFS, which lets me format a drive as NTFS. I also have the original folder structure.
To answer your question - the ProRes files were provided by a shooter that our client hired without considering whether or not they could work with his files. They're not video professionals, as you can probably guess.
Using ExFat means you won't need any 3rd party add-on on either end and will work on all the machines, not just the ones with add-ons. We use it all the time for external drives.
OK. If your client simply can't use the ProRes for any reason, then you'll have to supply them with something else.
One option is to find out how that shooter acquired the footage? Does he have only ProRes originals (shame on him if yes), or are they copies of the original footage? If copies, get the originals.