qwinsta --"Error [5] - Access is denied"

Question

I am getting the "access is denied" error even though I have no problem connecting with Remote Desktop Connection. My computer is Win7, the targets are WinXP or Server 2003.
Perhaps I am specifying the SERVER name incorrectly:
qwinsta /SERVER:XXYYZZ02
I have tried
qwinsta /SERVER:\\XXYYZZ02
qwinsta /SERVER:domain\XXYYZZ02
qwinsta /SERVER:domain/XXYYZZ02
qwinsta /SERVER:1.2.3.4

Am I doing something wrong? TIA...
(The problem I'm trying to solve is several support personnel needing to connect to the same servers and disconnecting each other mid-session.)

Answer 1

Found on Dell website, this worked for me same issue.

This means the remote RPC component failed to execute the requested operation. It is because it is not allowed to operate on terminal service (Remote Desktop) through RPC by default. To modify this setting to enable Remote Desktop API through RPC, you need to find the following registry key:

HKLM\SYSTEM\CurrentControlSet\Control\Terminal Server

Then add a DWORD value named “AllowRemoteRPC” and change its value to 1.

In my case it was set to "0". I changed it to 1 and all was good.