FWIW I just tried PK_tether on Windows 10 Pro 64bit - it worked like a charm. I didn't even have to install it, just ran the unzipped files. I won't even attempt to install PPB/PDL 3 and Remote Assistant on Win10.
As Adam pointed out the K10D does not have live view. Remote Assistant simulates the viewfinder display and shows the preview image after taking a shot. That is probably what you recall as Liveview. The major difference between RA and Pk_tether is that RA has a sexier interface, you can access some of the camera settings (time/date location etc.) and setup a User mode. All the other functions are the same.
It may have Liveview with the K20D. I don't know.