I use Windows 7 SP1 and an NVidia Geforce GTX550Ti card. I am running the lastest drivers, updated from the NVidia site. All of a sudden, the pc has been crashing, sometimes recovering with the following displayed "Display driver nvlddmkm stopped responding and has successfully recovered.". Other times it does not recover and I have to reboot. It happens spasmodically and with no regular pattern. Any ideas as to why or what else I can do ?
iscanut2 had a similar problem to yours with the 'recovered' pop-up and it will be a driver issue I think. Had to uninstall the version in programs and features first, reboot, then installed the working version for me which is GeForce 340.52 - release date 29/07/2014. Not removing an older version seemed to create the issue. Uninstalling via prog & features, rebooting, then using Nvidia GeForce Experience to update it has solved the problem for me. GTX 550 Ti card.