Hey everyone, I just started getting this issue today as well, and this is what I did fix it.
Quick Note: I am on Windows 11 using an Aurora R13, so I can't say this will work for people who aren't. The most recent version of 6.x (the one from October last year, which is what I used and linked to in step 3) is only compatible with Windows 11. When you click on the link in Step 3, scroll down and double-check that your device and operating system are compatible with the version you're downloading. There are two other versions available, which you can find in the "Other Available Versions" drop-down in the link provided (one from Aug. and one from Apr.). The one from August says it supports Windows 10.
I originally tried to install the version from April, and the Package Manager blocked the installation, so if you try one version and it doesn't work, another verison may.
Step 1: First thing is you want to kill that notification so you can use your computer again. Press Ctrl+Shift+Esc to open the Task Manager and locate anything labeled with AWCC that is running. Right-click on it and select End Task. This will stop the pop-up so you can go uninstall Alienware Command Center in peace.
Step 2: Go to Settings>Apps>Installed Apps>Find Alienware Command Center. Click on the three dots to its right and uninstall it. You don’t need to uninstall the AlienWare Command Center Package Manager, just the Command Center (For me, it wouldn’t even let me uninstall the Package Manager). After uninstalling the Command Center, restart your computer. Hopefully, after restarting, a few minutes have passed, and no more notifications.
Step 3: After the restart, go to Alienware Command Center 6.x - Full Installer for Alienware/Dell G Series System | Driver Details | Dell US to download the newest version of the Command Center (The Command Center is no longer available from the Microsoft Store).
After the download is finished, open up the folder (IM_Web_v6.10.15.0.zip) and run the “AWCCInstallationManager” inside.
Follow the instructions and agree to the licenses, and the installation should begin. Its gonna take a while, and if you're like me its going to be buggy, telling you the “Download is Complete”, prompting you to restart your computer when it's only 15% of the way there. Ignore the notifications and only restart when the Installation Window is finished and asks you to reboot.
After the reboot, you should have the newest version of the Command Center installed and no more notifications locking you out of using your PC.