Excel is autocopying Cells

[Bepster]

I am trying to use excel and it suddenly started copying cells across every sheet of my workbook.  Can someone please tell me how to stop this? I am glad I found this out by switching to another sheet before it destroyed anymore of my work.  

[#2 · Accepted solution]

@Bepster 

I figured it out, for some reason, I had grouped all my sheets.  So when I entered data into one sheet it copied across all sheets.