Thanks. I found the answer with google and my instruction manual. Had to go in and make a few changes then the "CArd" went away. Thanks for your help!!Page 21 of the T3i Instruction Manual shows Card in the viewfinder means 1 of 2 things:
1. There is no card in the memory card slot.
2. The memory card has an error.
If there are any error codes displayed on the rear LCD - see page 287.
You might try removing the battery for several minutes. That lets capacitors in the electronics drain and is a kind of power-on-reset.