Just an update..I fixed this by
Installing a NEW library location from central (a folder called Orbx2)
Then reinstalling TE North from Central to see where it went...
It was Orbx2/xp11/TrueEarth Great Britain North/Custom Scenery/ then the relevant separate TE folders..
Quite surprising it went into so many sub folders. !
SO..I then copied all other Orbx stuff to a similar location... then went for INSTALL again on all
It then verified the files in that new location and accepted them
Seems a very long winded fix, but at least its now working
Hope that helps someone else
Thanks Jon for the help
Bil P