Here are some methods to avoid and remove "Class Not Registered" error in Windows OS.
Method 1 - System File Checker Scan
1. Firstly, goto Start -> All Programs -> Accessories -> right-click on Command Prompt and select "Run as Administrator".
2. Open Command Promt, type sfc /scannow and press Enter.
3. Now it will scan and repair any error from your computer.
Method 2 - Safe Mode
You can avoid this error by running your PC in safe mode.
To do so, follow these steps.
1. Start you PC and immediately press/hold F8 button.
2. In the next screen, select "Safe Mode" from the list.
Method 3 - System Restoration
1. Start your PC/Laptop as Administrator.
2. Goto Start -> All Programs -> Accessories -> Tools -> click on Restore.
3. In the new window, click "Restore my system to a prior period" and then click on the Next button.
4. Now restore your PC by selecting the most recent restore date from the list.
5. Once done, reboot your PC.
1. Download the program given in the reference link below.
2. Then install, open and click on scan button.
3. Once done, click on "Repair Errors" button.
4. Reboot your PC.