How to Fix Runtime Errors on Windows

What Causes This?

Runtime errors usually happen when a program tries to use a file, library, or system component that is missing, corrupted, outdated, or conflicting with something else on your PC. Common causes include damaged app files, broken Visual C++ runtime components, leftover files from old software, malware, or Windows system file corruption. In some cases, the error only appears with one app; in others, it points to a wider Windows problem.

Common Symptoms

• A pop-up says “Runtime Error” when opening or using a program
• An app crashes or closes suddenly during startup
• Errors appear after installing, updating, or uninstalling software
• The same program works on another PC but fails on yours
• Windows feels unstable or shows repeated application errors

How to Fix It Manually

1. Restart your PC

   • Save your work and restart Windows normally.
   • After rebooting, open the app again and check if the runtime error returns.
   • This can clear temporary conflicts or stuck background processes.

2. Update Windows

   • Press Windows + I to open Settings.
   • Go to Windows Update.
   • Click Check for updates and install everything available, including optional quality updates if relevant.
   • Restart your PC after updates finish.

3. Repair or reinstall the affected app

   • Press Windows + I and open Apps > Installed apps.
   • Find the program showing the runtime error.
   • Click the three-dot menu next to it and choose Modify or Advanced options if available, then use Repair.
   • If repair is not available or does not help, uninstall the app, restart your PC, and install the latest version from the official website.

4. Reinstall Microsoft Visual C++ Redistributables

   • Many runtime errors are caused by damaged or missing Visual C++ runtime packages.
   • Press Windows + R, type appwiz.cpl, and press Enter.
   • Look for entries named Microsoft Visual C++ Redistributable.
   • If the app gives a specific version in the error message, reinstall that version from Microsoft’s official site.
   • If you are unsure, reinstall the latest supported x64 and x86 packages, then restart your PC.

5. Run System File Checker and DISM

   • Click Start, type cmd, then right-click Command Prompt and choose Run as administrator.
   • Run this command and wait:
     1. sfc /scannow
   • After it finishes, run:
     1. DISM /Online /Cleanup-Image /RestoreHealth
   • Restart your PC after both scans complete.

6. Check for startup conflicts

   • Open Task Manager with Ctrl + Shift + Esc.
   • Go to the Startup apps tab.
   • Disable non-essential startup items one by one, especially third-party utilities tied to the affected app.
   • Restart and test again.
   • If the error started recently, also try a clean boot using System Configuration (msconfig) to rule out software conflicts.

7. Scan for malware and remove leftover software files

   • Open Windows Security from the Start menu.
   • Go to Virus & threat protection > Scan options > Full scan.
   • Also remove old app leftovers from programs you no longer use, since broken files and registry traces can trigger runtime problems after updates or reinstalls.

Fix It Automatically with Kudu

Kudu can help when runtime errors are caused by leftover app files, broken uninstall traces, and general system clutter that keeps interfering with software. It scans for junk, cleans out old software remnants, and helps reduce the conflicts that often trigger runtime errors on Windows.

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