If you have updated your nvidia drivers lately some of the versions have not been too good for mining, try updating to the latest one, or just a reboot could also work as a quick fix.
No, not update. Now new profile INTEL interferes with NVIDIA profile. I have a CPU profile for the Intel I5. Now, I have to stop de CPU miner and then start de Nvidia profiles miners. Once they started mining, I can start the CPU profile. Needed a reboot on the PC for this, if not it did not work
