I'm going to assume you never reproduced the "pink screen" issue with an external monitor attached to your laptop.
296.16 has had some reports of "pink screen" lockups during YouTube playback. I recommend you perform a clean install of the NVIDIA 304.48 BETA driver. Choose "Custom Install" and then check the "Clean Install" checkbox.
I recommend you boot into Windows Safe Mode for this installation. It will disable other running drivers (such as Antivirus) that may interfere with your video driver installation.
If you do not wish to install the latest NVIDIA 304.48 BETA, then go for the 285.62 or 295.73 WHQL drivers.
G74SX-A1 - stock hardware - BIOS 202 - 2nd Monitor VISIO VF551XVT