Copy Paste Functions no longer working in Excel

[PAH5551]

I am not a power user of Excel - but I have been using excel for years and can work my way around.  Copying rows and columns was a simple task but somehow in the last few weeks the function stopped working.  I also can't simply highlight cells by holding down my cursor.  So moving cells, is impossible.  I have searched for answers but nothing works.  

[#2]

@PAH5551 I have same / similar experience starting today. ctrl-c, move to another cell, ctrl-v, value of first cell is pasted into second cell, not the formula. Dragging seems to work as it did in the past. But that only helps when the destination is adjacent to the source cell. Wow.

[#3]

@PAH5551 Sorry, I am completely wrong. In my case, another open workbook is responding to ctrl-v somehow. My apologies.