When a user wants to utilize their existing per-socket, per-core, or per-virtual machine software licenses for a Microsoft Windows server running on AWS, which Amazon EC2 instance type is required?

Spot Instances are spare EC2 capacity offered at a discount and are not suitable for license mobility requiring dedicated physical hardware.

Dedicated Instances run on hardware dedicated to a single customer account, but they may share the same physical host with other Dedicated Instances belonging to the same customer, which might not meet specific license requirements tied to physical hardware.

Amazon EC2 Dedicated Hosts provide physical EC2 servers dedicated for your exclusive use, which allows you to bring your existing eligible software licenses that are licensed per-socket, per-core, or per-VM.

Reserved Instances are a billing discount applied to instances for a committed term and do not provide dedicated physical hardware for specific licensing needs.