Microsoft Office Outlook fails to open with the following error:
This application has failed to start because MSVCR80.DLL was not found. Re-installing the application may fix this problem.
Download the Diagnostic
There are certain situations when missing entries in your registry and registry corruption causes this problem. Try running a registry scan to identify if there are any such issues.
- Click the button below to download and install the Diagnostic
- Perform a Registry scan and fix any problems detected.
- Restart your computer.

Estimated Download Time: 10 Seconds
Correct File Registration Issues
Each Dynamic Link Library file is registered in system Registry upon installation of a program. As Registry is the central database accessed by your operating system and applications, it becomes corrupted. In this particular case, MSVCR80.DLL Registry entries are deregistered. Reregister them again using command-line instructions.
For Windows 10/ 8.1/ 8:
1. Open elevated Command Prompt. (Press Windows Key + X, choose relevant option)
2. Execute following commands one by one:
- takeown /f MSVCR80.DLL
- regsvr32 MSVCR80.DLL
3. To complete the process of reregistration, restart your machine.
For Windows 7/ Vista:
1. Click Start; type “CMD” in the Search Box.
2. Right click it from Search Results, choose Run as administrator option.
3. Refer Steps # 2-3 under Windows 10/ 8.1/ 8 section.
Obtain Missing File
The MSVCR80.DLL file may be renamed, moved, deleted or corrupted. Do a thorough search on your hard disk to find the file. Copy it to C:\Windows\System32. Do NOT download it from third party sources as your system may get infected.
- Use the Search box in File Explorer. (File Explorer is known as Windows Explorer in earlier versions of Windows)
- Check contents of Recycle Bin.
- Reinstall Microsoft Office Outlook.
Get Rid of Corrupt Manifest File
One or more recently installed Outlook plug-in has saved data in a file named outlook.exe.manifest and corrupted its default configurations.
1. Exit Outlook completely. Close its system tray icon to avoid file in use error.
2. Open File Explorer icon.
3. Open following directory:
- For 32 Bit: C:\Program Files\Microsoft Office\Office <Version>\
- For 64 Bit: C:\Program Files\Microsoft Office (x86)\Office <Version>\
4. Delete the file named outlook.exe.manifest
5. UAC will prompt you for confirmation. Go ahead and confirm.
Perform Office Diagnostics
The Diagnostics program repairs a problem with the Office system.
For Windows 10:
1. Exit all instances of Microsoft Office.
2. Click Start > All Apps > Microsoft Office > Microsoft Office Tools > Microsoft Office Diagnostics.
For Windows 8.1/ 8:
1. Click Start.
2. Type “Microsoft Office Diagnostic” in the Search Box.
3. Click Apps icon.
4. Open that from Search Results.
For Windows 7/ Vista:
1. Click Start; type “Microsoft Office Diagnostic.”
2. Press ENTER.
Verify Office Add-Ins
One or more add-ins are not functioning correctly. Run Outlook into Safe Mode, i.e. disable all add-ins.
Method # 1: While opening Outlook, press and hold Ctrl key of your keyboard.
Method # 2: Press Windows Key + R, type “outlook.exe /safe” (without quotes) and press ENTER.
Reinstall Essential Component
Microsoft Office Outlook requires Microsoft Visual C++ 2005 to be installed. Check if the error appears due to the corruption of Visual C++ package.
For Windows 10:
1. Click Start | Settings.
2. Click System | Apps & Features.
3. Type “Visual C++” in the Search box.
4. Right-click “Microsoft Visual C++ 2005 Redistributable” and choose Uninstall.
5. Follow the on-screen instructions.
For Windows 8.1/ 8:
1. Press Windows Key + X; choose Programs and Features.
2. Uninstall Microsoft Visual C++ 2005 Redistributable from the list of installed apps.
For Windows 7/ Vista:
1. Type “Programs and Features” in the Search Box of your Start Menu.
2. Open that from Search Results.
3. Remove Microsoft Visual C++ 2005 Redist.