I am not a member but had this problem which was resolved after reading one of the members advice with a bit of extra leg work. It worked before logging on but would stop afterwards. It was turned off. To switch it back on:
1) click on the 'show hidden icons ' button at the bottom of the screen
2) click on the computer screen icon
3) click on 'pointing devices'- mouse properties opens up
4) select settings
5) a selection window opens up. I found the 'tapping' selection box unticked
6) tick the 'tapping' and then 'ok' then 'apply'
All good after multiple attempts to fix. Hope this helps someone