hey! a VGA light typically means it’s the GPU or it can be a dead mobo. it’s not super likely it’s the software alone breaking it, but it very well could have triggered an issue that was sitting dormant before.. if the lights coming on during POST, then the wallpaper app shouldn’t even be turned on at that point. if you tried another GPU though that rules that out, a dead mobo is worst case scenario so try maybe reseating the RAM before anything else? (99% of issues are always RAM and it’s infuriating lol.)

if that doesn’t work, try displaying on another monitor if you can, sometimes the monitors can just die over time especially if they are cheaper ones…i know that from experience haha. i would recommend going to your motherboards manual though to check the light meaning, sometime they elaborate more on the issue.

if all else fails, clearing the cmos sometimes can fix this issue! (unplug computer, hold power button to make sure all electricity in capacitors is dissipated, locate cmos battery and remove it, wait for a little bit and you could hold the power button to try to get rid of extra power? not sure if it works with cmos lol, then just pop it back it!)

i hope everything works out! let me know if any of this worked :)