Don't know, do you get any errors? Perhaps you can't paste because you didn't copy something first? How old is your keyboard?
I do know that your question probably will end up here:
When I use IE (which is as little as possible) I get a popup notice asking me if I want to allow access to my clipboard.
"When I use IE (which is as little as possible)"
My momma always said Windows was like a box of chocolates ..
(With apologies to Tom Hanks)