Hi All,
Thanx for all the suggestions, I found them very helpfull. I did register with NorbiesWorld and had my scan results checked out -all OK.
After trying all the suggestions given here and not having any success fixing the problem, I decided to take drastic action and do a Windows repair install - after backing up of course! Success, all is now working as it should.
My cure of the problem still remains a mystery but thanx to everyone for their help.