Looks like some problem with the graphics card driver, the bus or the graphics card itself.
The graphic card works just like a printer, if you try to send raw text to it or any data that doesn't correspond to its protocol, it will print this data in the screen as text. It seems to me you are experiencing something like that.
Try updating the drivers and clean the contacts on the PCI Express slots with a soft rubber and see if it helps.
Make sure your PSU is sufficient to power this graphic card. They are quite demanding, and if the PSU cannot power them properly you will experience issues.
If the problem persists, the card may be defective. Try another card if you have one available, or try your card in another computer to determine where the problem is.