Decrypting Files Copied from EMS Encrypted Thumb Drive

Hello,

I am attempting to decrypt files I copied from my Dell Encrypted Thumb Drive. 

I encrypted the thumb drive with my Dell laptop and then I added image files to it.  That part went fine.

My image printer service requires non-encrypted thumb drives, so I took the encrypted thumb drive to a non-encrypted computer, and copied those files from my encrypted thumb drive to the hard drive, and from there to a non-encrypted thumb drive.

(My mistake was to not copy the files from the EMS explorer, but instead the Windows explorer, and thus I copied encrypted, rather than non-encrypted files, to the non-encrypted computer.)

I repeated this process, deleting the previous files on the thumb drive by copying the subsequent files over them, before I realized my mistake.  In other words, the original encrypted files no longer exist on my encrypted thumb drive.

I was wondering if there is a way to decrypt the files I copied to the computer?  I looked at the files on the thumb drive, and I noticed the VolumeInfo.xml file, which shows a shield date created several months ago.  Also, there is a ShieldID. 

Can this VolumeInfo file be used to decrypt?

Thanks for your help in this!