Thanks Coling,
In the end - as it was driving me up the wall, I uninstalled MFP, through control panel. Then remove stray directories. Then ran CCLEANER registry tool , backed up registry and removed what it found. After all that I went into REGEDIT, and still found entries to remove.
The rebooted, and downloaded MFP v8.1.0.1 and now all is fine. I shall be going through the trigger that may have caused the problem before using it.
thanks again,
David