I am using Excel 2019 now, however I just noticed you are using 2010. I vaguely remember sometimes on a copy of a workbook sometimes the Ctrl + C or copy from the menu would not capture everything into the clipboard and when you go to paste you only have three choices. Something appears to prevent you from getting the entire paste menu. I'm trying to remember how I solved that issue as I do remember it happening to me.

I just tried a paste special after I copied a worksheet from the corner and selected all except border and my formula's and conditional formatting came over into my new Excel workbook I opened. I also tried ALL the default and everything copied.

If you can get your paste button to give you this option, it might be an alternative.

Okay, I did a quick search on Excel 2010 and someone mentioned that Skype interferes with the copy and paste features. They uninstalled Skype and it worked for them. Had the same issue as you did.