Before we start, specs:
OS: Win 11 Home 22H2 (22621.1702). My current OS is installed from the Windows 11 Installation Media on a USB
GPU: Intel UHD Graphics 620 (Internal) + Nvidia GTX 1660Ti (External, the cause of the issues)
CPU: Intel(R) Core(TM) i7-10750H CPU @ 2.60GHz
Memory: 512 SSD + 2TB HDD (exact drive type unknown, factory drives, I can find out if need be)
RAM: 16Gb (exact brand unknown, factory RAM)
BIOS Version: Insyde Corp. V2.06, 19/08/2021
Model: Acer Nitro AN515-55
Please let me know if more information is required, I will do my best to provide it.
In early May, my laptop blackscreened without notice, and I took it to a repair shop for repairs. After the repairs were complete (which involved replacing a burned chip, whose purpose I had sadly forgotten and the repair guy said was unrelated to the GPU), I tested the laptop and saw my GPU was missing in the Task Manager (it still is).
I looked at the Device Manager and I saw this issue: Windows has stopped this device because it has reported problems. (Code 43)
I disabled and re-enabled the device, and I saw this: This device is working properly.
The GPU still did not exist on the Task Manager Performance list, so I restarted the laptop. After restarting, I rechecked the Device Manager and saw the Code 43 had persisted. I attempted to open Nvidia Control Panel. I received no response from the Control Panel. I tried everything in this link (run in admin, End NVIDIA Background Processes, Restart NVIDIA Display Container Service, Repair & Reset the NVIDIA Control Panel App, Update Nvidia Drivers) to no success of reopening the Nvidia Control Panel, though I was successful in opening the software license agreement for the Control Panel.
I also uninstalled and reinstalled the latest version of my GPU's driver, both from GeForce Experience and Nvidia directly, both with an express download and a custom download where I used a clean install to clean previous drivers. All download attempts were successful, with the installer not reporting any issues.
On GeForce Experience, I also encountered this screen, stating that "No driver found: Click continue to install the latest Game Ready driver or Studio driver".
I attempted to reset my laptop, first with the internal "reset PC" function with the documents retained. Then I attempted to reset with the documents deleted.
It did not help.
My final attempt involves downloading the Windows 11 Installation Media on a USB and clean installing Windows from there. I followed this guide for my clean installation, with the only deviation being that instead of clearing the partition of only the system hard drive, I also cleared the partition of the external HDD.
It also did not help and I had to re-partition the external HDD. I restarted the laptop and there was no improvement.
Please let me know if more information is required to resolve this issue.