The question here is what would you like to accomplish. But if the intention here is to install the whole package including Secure Endpoint client then that will be only possible either with separate installation like Ken pointed out with Secure Endp...

One thing to consider as well and make sure this was completed:   Note: As of connector version 7.5.7, installation requires OS patches with Trusted Signing as required by Microsoft. Note: As of connector version 8.1.3, installation requires OS patch...

You might have to try first update those endpoints to legacy version 7.x and then try to update to 8.x.Unfortunately there is no guarantee with such as obsolete connector version that this will work. Ultimately with connector that old I would recomme...