Windows Server 2003 R2 no contact on Hyper-V Windows Server 2008 R2 Standar edition

I have installed W2k3 R2 VM, since it had at start no network detected i added a legacy network adapter and installed intergration services. Now by recommendations on the comments of ths question I change the legacy network adapter to a tradicional virtual network adapter.

The server is used as DNS and a Domain Controller. Users are working as intended with no problems.

Still i get the "Heartbeat: No contact" message but the icon shows the activity of the server.

What did i do wrong ?

P.S.

As i noticed, i cannot install intergration services as it retruns an OS icompatibility error and update via Windows Update is not possible returning a '0x80072EFE windows update error'

You have this issue because you are running an unssoported for Hyper-v version of Windows Server 2003 R2. You are running Windows Server 2003 R2 SP1.

You should install the Service Pack 2. Then install the Hyper-V integration services and restart the virtual machine. You will have the virtual NIC working.

Alternative if you really cannot install the Service Pack 2, you can manually install the driver from the integration services ISO using the device manager (devmgmt.msc), but this is not recommended.