Help needed to start Peppermint 6 (SOLVED)

I am writing this on the win7 machine as my main linux computer has a serious problem.
I have been playing around with my computer lately and I have done something wrong.
This evening when I switched on the computer started as normal, put up the taskbar at the bottom of the screen as normal, when I moved the cursor (using the mouse, I have the touchpad disabled) over the menu and clicked nothing happened.
I tried left and right clicking but nothing happens, I shut down using reisub and started up again.
When I started the second time I can right click on screen 1 icon and get a menu that allows me to run Nemo as root, it is siting waiting for me to enter my password. I don’t want to click on anything else and get deeper in to the mire.
Can anyone help ?
EDIT Sorry for the panic :-[ I have just replaced the mouse, the left button had stopped working.

LOL … always the obvious that catches one out ;D