Windows Store app install fails with error code 0x80073CF9

When does this error show up?

You click Install on an app from the Microsoft Store—maybe something small like Spotify or a game—and it gets stuck at 0%. After a few minutes, you get error 0x80073CF9. It's not the app's fault. It's something deeper with Windows itself.

I've seen this most often after a Windows update (especially one that didn't go smooth) or when your C drive is nearly full. One client last month had it because their SSD had 3GB free and the app needed 5GB. But the error doesn't always tell you that.

Root cause

The Windows Store uses a service called TrustedInstaller (part of Windows Modules Installer) to install apps. When that service is stuck, corrupted, or blocked by low disk space, the installer throws 0x80073CF9. Another common cause: a corrupted Store cache.

Think of it like a clogged pipe. The water wants to flow, but something's in the way. You have to clear that clog before you try again.

Fix 1: Clear the Store cache first (fastest)

Skip the registry edits and long scans for now. Try this:

1. Press Windows Key + R, type wsreset.exe, press Enter.
2. A black command window will appear. Wait—it might sit there for 30 seconds or more. Don't close it.
3. After it finishes, the Store will open again. Try installing the app one more time.

If it works, you're done. If not, move to Fix 2.

Fix 2: Run the Windows Store troubleshooter (don't laugh)

Yeah, I know—troubleshooters are hit or miss. But the Store one is actually decent. Here's how:

1. Open Settings (Windows Key + I).
2. Go to System > Troubleshoot > Other troubleshooters (Windows 11) or Update & Security > Troubleshoot > Additional troubleshooters (Windows 10).
3. Find Windows Store Apps, click Run.
4. Follow the prompts. It'll try to fix common issues like broken permissions or misconfigured services.

This fixes maybe 30% of cases. Worth the 2 minutes.

Fix 3: Repair the Store app with PowerShell (my go-to)

If the cache reset didn't help, we need to re-register the Store. This is what I do for clients 9 times out of 10:

1. Right-click the Start button, choose Windows PowerShell (Admin) or Terminal (Admin).
2. Type or paste this command exactly:

Get-AppXPackage *WindowsStore* -AllUsers | Foreach {Add-AppxPackage -DisableDevelopmentMode -Register "$($_.InstallLocation)\AppXManifest.xml"}

3. Press Enter. It might take a minute or two. You'll see a bunch of text scroll by—that's normal.
4. Close PowerShell, restart your PC, and try the install again.

Had a client last month whose entire print queue died because of this same error. This command fixed both.

Fix 4: Check disk space and run DISM/SFC

If the error still shows up, it's time to check system health. Low disk space is the sneakiest cause. Open File Explorer, check your C drive. If it's under 5GB free, free up space first—delete temp files, empty Recycle Bin, uninstall unused apps.

Then run these commands in an admin Command Prompt or PowerShell:

1. DISM /Online /Cleanup-Image /RestoreHealth — this scans and fixes system image corruption. Takes 10-15 minutes. Be patient.
2. After that finishes: sfc /scannow — this fixes corrupted system files.
3. Restart your PC.

These two commands together fix 95% of lingering Store issues.

What if it still fails?

If none of these work, you've got a deeper problem. Here's what I check next:

• Your antivirus: A real-time scanner can block Store installs. Try disabling it for 5 minutes (just to test). Bitdefender and Norton are famous for this.
• Windows Update: Run Windows Update manually—sometimes the Store needs a recent update to work right. Go to Settings > Windows Update > Check for updates.
• Create a new user account: Maybe your user profile got corrupted. Create a local admin account, log into it, and try the Store from there. If it works, you know the problem's with your old profile.
• Reset the Store app completely: Open Settings > Apps > Installed apps, find Microsoft Store, click the three dots, choose Advanced options, then Reset. This nukes the app back to factory state—but you'll lose saved data.

One last thing: if you're on Windows 10 version 1809 or older (common with old business PCs), the Store can be buggy with this error. Upgrading to a newer version of Windows usually fixes it for good.

Good luck—you'll get it sorted.