
Which ever one it is - I think you will find a solution for yourself at Crossloop.
Crossloop is a free screen sharing tool which anybody can use with anybody else. It was started as a free way for families to share their computer screen with each other and help each other with computer problems. This is still possible and it now is a great way for the helpers to earn some extra money.
Here is a great video demo of how this tool works:
To learn how to use Crossloop as an "expert" or a student, read more