Hello,
I have the original Alienware 17 from back in 2013. I recently upgraded to Windows 10, and my nVidia GeForce GTX 770M disappeared from Control Panel and Device Manager. However, for the last month, all was well.
I tried all things I could think of and read about on the Internet to no avail for any option. All it would show is Microsoft Basic Adapter, or Intel 4600. Since Microsoft Windows 10 users do not have the option of choosing which updates to perform if they
do not have Windows 10 Pro, I noticed the latest update installed BIOS version A14.
Once I downloaded A13, and the GeForce 355.60 driver for Windows 10 64-bit computers, I reverted back to A13, and the computer detected the nVidia again.
Just thought this might help for those users who have recently experienced this on Windows 10 with an Alienware laptop or desktop.
Thanks.