Is there any way to get a file transfer from an Olympus OM-D EM1 Mark II to Windows XP? As far as I can tell, the only way to get files off the camera is with Olympus Viewer 3 which does not work on XP. Viewer 2, which does work on XP, does not appear to be able to communicate with the camera.
Keep in mind that the memory card in the camera is just a standard removable data storage device, and the photos on the memory card are just standard files. You don't need any special software to transfer files like this.
Take the memory card out of the camera and just use a card reader.
I run Olympus Viewer 3 version 1.5 on XP, Olympus UK shows that XP is unsupported after v1.5, the next being v2.0 released 01/27/16.
Trouble is I can't see anywhere to download it anymore. It's worth checking around as I've noticed in the past that the various Olympus sites around the world often have different content.
I don't know how I got hold of it, or if v1.5 will support your camera. I'm guessing not as the mark II came out in 2016. The only thing I can suggest is using an old installation disk to load up an earlier version and (if necessary) then using the software's update service.