Recovering Encrypted files

I ahve a pc that I copy my files to a exturnal HDD and one of the files was encryptyed. after reformating the entire PC I cannot open the Encrypted files on the back up disk. Now the exturnal HDD is NTFS. is there a third party utility that I could download to un-encrypt the encrypted files? I have tried to take ownership of the files . I can see then now but I still cant move or copy them. Please help