>I have a VM server which takes a long time to load, whenever I connect to RDP. All other VMs are quite fast. But, that particular one is somewhat or a problem. It is a domain controller, however, so maybe that would be normal. Anyone can comment on this?

How long is "a long time to load"?

The fact that the VM is a DC should not, by itself, cause sessions on it to load slowly. I regularly connect to several DCs via RDP and performance is good, the same as connecting to non-DC servers or workstations.

Hopefully, with a server, you don't have any roaming profiles configured i.e. when you start your session on the DC a large user profile is being pulled across the wire from some other machine.

Do you have any processes set to auto-start when your session loads?

Assuming nothing above is out of the ordinary, go into Task Manager/Resource Monitor and check the following, in order:

1. RAM usage. DCs tend to either have a lot of other stuff running on them (e.g. Small Business Server) or basically nothing else. In either case the VM can be RAM-starved; the first case with not enough allocated to support all the processes and services, the latter because the admin cuts its allocation down to the bare minimum (e.g. under 1GB) so there's nothing left for profiles when someone logs on remotely. If the VM gets starved for RAM it will page to disk, which is slow

2. Full (more than 95% in use) or slow disk subsystem underlying the VM

3. Check the Event Logs on the DC - primarily System and Application. Look for errors first. If nothing seems obviously wrong also look at non-error events. I've seen cases where improperly configured certificates or authentication causes dozens or hundreds of messages per second to be written to the Event logs, which bogs down the whole machine