It could be your card overheating, make sure your system is well-ventilated for sure.
It could also be a driver issue, I'd recommend you get drivers from Acer directly, as they built/configured the system and will have a more specific driver than the general one that Windows Update provides.
Finally, if it still continues, you might considering turning off the "automatically restart when errors occur" so that you can potentially get a chance to see the exact error message instead of immediately rebooting without a chance to see what happened. Here's how to Disable Automatic Restart on System Failure. Note that next time a failure occurs, you might have to reboot yourself by holding the power button, but this might help you troubleshoot.
- Press Windows Key + R then type sysdm.cpl and hit Enter to open System Properties.
- Now switch to the Advanced tab then click on “ Settings ” under Startup and Recovery.
- Make sure to uncheck “ Automatically Restart ” under System failure.
- Click OK then click Apply followed by OK.
- Reboot your PC to save changes.