Many enterprises do not have a choice when it comes to virtualization platforms. Currently, HipChat Server only makes OVA images that are supported on VMWare or Virtualbox-based solutions.

Microsoft Hyper-V is also a very popular choice among customers, and they may not have the luxury of standing up VMware just to run HipChat Server.

Please consider making VHDX images available for HipChat Server to ease the pain of administrators having to convert the OVA images themselves.

The steps right now, in a nutshell:
1. Download HipChat OVA
2. Extract VMDK files using an unzipping utility.
3. Convert VMDKs to VHDs/VHDXs.
4. Create a Hyper-V virtual machine, attach VHDs/VHDXs and power up.
The VMDK -> VHD -> VHDX is just an idiosyncracy - it is possible to go direct from VMDK to VHDX. Or some users may just stop at VHD.