mccoady--I understand this is happening only some of the time on certain emails, webpages, text files, etc. Correct? "Sometimes" can be hard to fix.
And I presume you mean Copy and paste--not Cut (certainly not from webpages).
Also you reference that the problem often occurs on email pages. You cannot "Cut" from certain email messages, such as those in the Inbox, though you should be able to Copy.
Are both you and your wife using the same keyboard?
You could see if the problem is with the Copy function by Copying and then opening your Clipboard. Is the copied material there? If no, or you do not have Clipboard installed, that could be the problem. If yes, that would suggest the problem is with the Paste function, but I do not know how to solve that, other than a System Restore to a date before the problem started.
I suppose there also is an outside chance Start|Run|type sfc /scannow|OK might help. Have your WinCD ready to insert into the CD-ROM drive.
If this has only started recently, have you added any new soft/hardware just before it started? You could uninstall.
Though it would only be a work around, I am sure you know there are at least three different methods to copy and paste.
All start with Highlight with mouse. Then
1) MenuBar Edit|Copy. Move to program where you want to Paste. Edit|Paste.
2) Control+C. Move to program where you want to Paste. Control+V.
3) Right click on highlighted material. Left click Copy. Move to program where you want to Paste. Right click in window. Left click Paste.
Often combinations of the above work. The Copy part puts the copied material into ClipBoard, from which any method for pasting should work.