GaurdianEdge wiped from external hard drive and need to access encrypted files

The organization I work for used GaurdianEdge to encrypt data on removable storage devices.  They have since switched to Symantic Endpoint Protection.  Initially GaurdianEdge automatically downloaded onto my external hard drive and I used the GE access program on the external harddrive to access my encrypted files without any issues for a couple of years.  Recently, the GuardianEdge access utility dissapeared from my external hard drive so I can no longer access the encrypted files on my external hard drive from my laptop.  When I plug the external hard drive into my work computer I can access all my files but I can no longer access any encrypted files on my external hard drive when it is plugged into my laptop as the external hard drive no longer has the GaurdianEdge access program.  Please help me understand how I can put the program back on my external hard drive to access my files or what Symantec Product I need for my laptop to be able to access the encrypted files on my external hard drive when it is plugged into the laptop.  I have the password so the only thing I need is to be able to access the encrypted files on my external hard drive when it is plugged into my laptop.  Thank you