Just to add to Jim's suggestion regarding unstill and reinstall.
- Close all other applications.
- Turn off your virus scanner.
- Then uninstall TMGv8.
- Re-boot your computer.
- Check whether your virus scanner is still turned off - if not, temporarily turn it off again.
- Install TMGv8 to right the same program folder you used previously.
- Re-boot your computer.
- If necessary turn your virus scanner on.
- Start TMGv8 and immediately check whether HELP is functional from within TMGv8.
FIXED!!
I did just as Vera said but before reinstalling I checked Program Files and ProgramData - there were TMG7 and TMG remnants there. So I deleted them and ran CCleaner on the registry - no obvious problems. I installed TMG8 and, hey presto, the Help function works.
Thanks all
Alan