Acrobat reader on windows 10

I recently upgraded to windows 10.

I would like to find my pdf's but when I go into documents I can only find some.

How do I find my missing pdf's?

They were stored in my hard drive but when I upgraded they disappeared.

Any help would be greatly appreciated!
I'm debating switching back to windows 7.

Z.

If you know the name of the pdf, use search. Once you find one, right click 'Open with' select Acrobat Reader and tick box at bottom, always open with this application. That should default the icon to Acrobat again.