Sometimes, you may face situation when you cant make our which Microsoft account you're using with OneDrive. In such cases, you need to use Onedrive's unique CID. You can see the CID - a string of 16 hex digits - in several places; one is as the name of the .dat and .ini files in this folder:
For example, 375B34CD4FCBE487.
Once you've found out what the CID is, you can look up the account username - email address - in the registry.
Open Registry Editor (press Windows key + R, type regedit and press Enter) and navigate to:
If there is more than one email address listed, click on each in turn. Its associated CID will be given in the right-hand pane.
In this way, you can figure out exact account associated with OneDrive.