Here's an update as promised.
Firstly I found you can use the right-click context menu Properties > Details Tab > Remove Properties and Personal Information and choose 'Create a copy with all possible properties removed'.
This did not remove very much but it did remove Date Taken which was what I wanted.
But you can only do one file at a time with this method so not very practical.
So I installed and ran 'BatchPurifierLITE' from Digital Confidence.
This removed a bit more than before - again including Date Taken - and, as the name implies, you can do a whole lot of files together.
The stuff then remaining consists of the Image Properties (for jpg's) such as dimensions, resolution, etc and the File Properties such as name, type, size, etc. This is stuff generated, I think, by Windows on the PC rather than by the device that took the photo and includes Date Created and Date Modified.
Unfortunately, in Windows Live Photo Gallery, Date Created then appears as 'Date Taken' so the confusion I was hoping to avoid when sharing the file with others might not be eliminated.
So finally I had a look at the photos that I have stored (and I've shared) on SkyDrive.
These have not taken much data with them, some of the image and file properties but not Date Taken, even from the originals, only Date Modified so that's not as bad as I thought it might be.
But I'd prefer Date Modified not to be there as I don't see what use it is to anybody really.
Sometimes computer systems do things just because they can, not because they are actually needed !