I used to keep my C drive in a removable tray so I could take it home and work there. As computers were upgraded I would just slot the drive into the new one. Surely this is only one use.
Yes, that does sound like only one instance of the program. Without the documentation not tell you want polices the company has about using more than one instance of the program.
A few yes ago the owners of software used secret methods to prevent people of reselling software soothers. When you buy software you only buy the right to use it on one computer. Also, Microsoft has been very o active in prevention of software piracy. The inner details of methods used are seldom published t to the public.
There may be a hidden file that must o be present to make the program work. Therefore, when you copy the hidden file might not be sent to the other PC. One example is a zero byte file that also hidden. In some cases the copy program ignores zero byte files.
Of course, I can not help you with any effort to circumvent this feature of the original program. That is why I just recommend you buy another copy.
In previous request like this from others, I have had the gut felling the the person asking is a professional pirate and wants to make hundreds of copies and resell them with the free information I might provide. Especially so when the price of the product is very reasonable for commercial use. **
I trust you do understand why I can not give you any more help on this.
** For non-commercial use there are many free programs to print labels.