Your error code is 0x00000050: PAGE_FAULT_IN_NONPAGED_AREA
Requested data was not in memory. An invalid system memory address was referenced. Defective memory (including main memory, L2 RAM cache, video RAM) or incompatible software (including remote control and antivirus software) might cause this Stop message, as may other hardware problems (e.g., incorrect SCSI termination or a flawed PCI card).
The driver cited as your problem is the Nvidia display driver nv4_disp.sys Many people have had issues with this; it is a common cause of BSODs. So...
1. Download Driver Cleaner Pro or Driver Sweeper (both have free versions) to your desktop screen and install.
2. Download the latest diver(s) for your video card but don't install them.
3. Uninstall your video card drivers and reboot your PC into Safe Mode. Run Driver Cleaner Pro or Driver Sweeper. If it doesn't find any video card drivers that is quite okay.
4. Reboot and install new video card drivers.
* Let us know if this resolved your issues.