If you are talking of highlighting files in file explorer you may highlight a block by clicking on the first one in the block then holding down the shift key and clicking on the last one in the block. If you want to highlight a number of files in a list click on the first one then hold down the control key and select the others.
No no, you start to highlight and on the bottom it tells you as you highlight more,
how many items you have highlighted, I want it to also show you what the size is and as you highlight more the are increasing
I think in Win XP you were able to do this but I don't remember