This article relates to our product Cloud Drive Mapper.

If you can't be certain that the drive letter you have assigned in the IAM Cloud portal is going to be available on all your users' machines, the SequentialDriveLetters feature allows you to create a list of possible drive letters that it will try in sequence instead. 


If enabled, SequentialDriveLetters will kick in if CDM attempts to map a drive to a letter that is already taken by something else. Perhaps a user has a USB drive occupying the letter F, and you are trying to map the user's OneDrive to the letter F. 

Without SequentialDriveLetters, CDM's attempt to map the F drive to the user's OneDrive will simply fail. 

With SequentialDriveLetters you can create a sequence of alternative drive letters for CDM to try instead. Perhaps your list is X,Y,Z. In this case if the F drive is taken, CDM will then see if the letter X is available first, if it is then it will map the OneDrive to the letter X instead. If X is also taken it will goto the letter Y, and so forth. 

It should be noted that if you have the Manage My Drives feature enabled, where the users can map their own drives, centrally configured drives will take priority. This includes centrally configured drives diverted by SequentialDriveLetters.

And so in the scenario above, if the X drive was actually mapped by the user using the Manage My Drive feature, the OneDrive mapping via SequentialDriveLetters would take priority and uproot the user-managed drive. 

Upon being uprooted the custom drive would continue upon the SequentialDriveLetter sequence and try to find another available drive. However if the sequence had come to an end without the custom drive finding another available letter in the SequentialDriveLetter sequence, the custom drive will fail. At this point the user would need to re-map whatever custom drive mapping they had to a different available letter manually using the Manage My Drive feature. 

Enabling SequentialDriveLetters

To enable the 'sequential drive letters' feature:

Add the registry string SequentialDriveLetters with the value as a comma separated list of letters, e.g: f,g,h,i,j,k,l

to either of the registry locations:

  • HKCU\SOFTWARE\IAM Cloud\CloudDriveMapper
  • HKLM\SOFTWARE\IAM Cloud\CloudDriveMapper

HKCU takes priority where values exist in both.

If you have any questions or need any further assistance, please feel free to contact our support team at