This is an update to my other post:
[Tutorial] Discord Freezing? Here's the Fix That Finally Worked for Me (Windows Notification Cache Issue)

Here's what I Found After 2 Months of Troubleshooting (Windows Notification System / Clock App)

What’s New

Over the past two months I’ve been deeply troubleshooting this issue and reading everything I could find. My original guide (notification cache reset) helped, but only temporarily, the problem always came back.

After a lot more testing, I found something that appears to be the actual source, not just a symptom. Since doing this, the issue has not returned for me. I’m sharing this in case it helps others stuck in the same situation.

The Symptoms

Everything works normally after boot, but after about 30–90 minutes:

• Discord freezes or UI stops updating
• Top half of Discord shows one channel, bottom shows another
• Snipping Tool works once, then stops
• Notifications stop appearing or behave inconsistently
• Restarting an app fixes it once, then it breaks again
• Rebooting temporarily fixes everything

This makes it look like a Discord issue, GPU issue, or driver issue, but it’s actually deeper in Windows UI infrastructure.

What I Found

The issue appears tied to corruption in the Windows notification / toast system, involving a built-in Microsoft Store system app:

Windows Clock app (Microsoft.WindowsAlarms)
Store ID: 9WZDNCRFJ3PR

This app is not just a clock. It registers background tasks and integrates with:

• Windows Push Notifications (WpnUserService)
• Toast notification system
• WinRT background tasks
• ShellExperienceHost
• Desktop Window Manager (DWM)

If this app becomes corrupted (for example after a Store update), it can slowly destabilize the notification/composition pipeline. Clearing the notification cache alone helped temporarily, but repairing this app appears to stop the issue from coming back.

What I Did (Important)

I did both parts below.

PART 1 — Repair / Reset the Clock App

1. Open Settings
2. Go to Apps → Installed apps
3. Search Clock
4. Click the three dots → Advanced options
5. Click Repair
6. If needed, click Reset

This rebuilds the app data and re-registers its background tasks and notification hooks.

PART 2 — Fully Clear Windows Notification Cache

Step 1 — Turn Notifications Off (Temporary)

Settings → System → Notifications → turn Off

Step 2 — Stop Notification Services

Press Win + R, type:

services.msc

Stop:

Windows Push Notifications System Service
(Service name: WpnService)

Step 3 — Kill Per-User Notification Process

Open Task Manager → Processes

Find:

Service Host: WpnUserService_XXXXX
(the ending letters/numbers are different for everyone)

Right-click → End task

This fully releases the notification database.

Step 4 — Delete the Entire Notification Folder

Press Win + R, paste:

%LocalAppData%\Microsoft\Windows\

Delete the entire Notifications folder
Do not open it — remove the whole folder. Windows will recreate it automatically after reboot with fresh database files.

Step 5 — Reboot PC

This forces Windows to rebuild the notification system.

Step 6 — Turn Notifications Back On

Settings → System → Notifications → turn back On

Result

Since doing both the Clock app repair/reset and clearing the notification cache:

• No Discord freezes
• No half-screen UI bugs
• Snipping Tool works all day
• Notifications behave normally
• No gradual UI degradation over time

For me, this has been a long-term fix, not just a temporary workaround.

The notification cache reset clears corrupted database files. The Clock app repair fixes a system Store app that hooks into notification and background task infrastructure. If the app feeding into the system is corrupted, the problem can return. Doing both addresses both sides.

If this fixes it for you too, reply so others know this is a real pattern and not just coincidence.