Not permitted? Not permitted by who?
This is the dumbest response I have ever seen to a legitimate question and not even close to helpful.
I've been a long time customer of ESET software and run a small home lab that doesn't need and won't benefit from ESET server software. Let alone do I want to pay even more money to use a product I already have and have paid for.
I think if ESET doesn't "permit" it's users to install regular, already paid for, software on server OS's before my current licenses expire I'm gonna seek out other antivirus/firewall software from other vendors and not return to ESET.