How to Select All ?

[pranavRBM]

when I went through many resources it says
"1. Click on the first cell you want to copy.
2. Scroll down to the last cell you want to copy.
3. Hold down the Shift key on your keyboard.
4. While holding the Shift key, click on the last cell you want to copy."
but I am unable to do it
What should I do?

[DonJayamanne]

Press Ctrl+ A to select all cells
Ensure you have clicked on a cell (outside a cell editor)

[pranavRBM]

Thank you for answering but it is still not working
nothing works except shift+(down or up arrow button)