How to remove OneDrive for Business / OneDrive Personal link from the Explorer Side Panel in Windows OS

For OneDrive for Business please follow the below steps:

Go to Run > Type Regedit > Search for "OneDrive - Company Name" and you will find the location

Computer\HKEY_CLASSES_ROOT\CLSID\{XXXX-XXXX-XXXX-XXXX-XXXXXX}

Where In the subkey System.IsPinnedToNameSpaceTree changed the DWORD from 1 to 0.

Important Note: Make sure you take a back up of registry before making any changes.

Reference article: https://support.microsoft.com/en-in/help/322756/how-to-back-up-and-restore-the-registry-in-windows

For OneDrive Personal
Go to Run > Type Regedit > Search for "OneDrive - Personal" you will find the location
Where In the subkey System.IsPinnedToNameSpaceTree changed the DWORD from 1 to 0.

For Personal mostly the key would be same {HKEY_CLASSES_ROOT\CLSID\{018D5C66-4533-4307-9B53-224DE2ED1FE6}.

Important Note: Make sure you take a back up of registry before making any changes.

Reference article: https://support.microsoft.com/en-in/help/322756/how-to-back-up-and-restore-the-registry-in-windows

After making changes in registry in both scenario restart the system and check you should not view the link anymore.