When starting a virtual desktop, the Desktop Delivery Controller will try and start the virtual machine a second time, causeing the "The attempted operation cannot be performed in the current state (Powered On)" error on the virtual machine.

The Desktop Delivery Controllers may not be in the same zone, causing issues.

Check the existing zones:

C:\>qfarm /zone

Zone Name            Data Collector
-------------------- -----------------
0                    SERVER1
192.168.1.0          SERVER2

Note the two zones.

The server can be moved to the other zone using either chzone.wsf of by joining the existing farm using CHFARM.

chzone.wsf
http://community.citrix.com/display/xa/Move+a+Server+From+One+Zone+to+Another+Zone

CHFARM

Set DSNPATH=\\server\share\Citrix\XenDesktop\DSN\MF20.dsn
Set DSNUSERNAME=DOMAIN\Username
Set DSNPASSWORD=Password
chfarm /joinfarm /ddsc:"SQL Server" /odbcuser:%DSNUSERNAME% /odbcpwd:%DSNPASSWORD% /dsnfile:%DSNPATH% /verbose /quiet

Once the DDC has changed zone, only a single zone and ZDC will be shown:

C:\>qfarm /zone

Zone Name            Data Collector
-------------------- -----------------
192.168.1.0          SERVER1

To check the zone of all servers:

C:\>qfarm /zone /online

Server Name          Zone Name               LBOff
-------------------- ---------------------- -------
SERVER1              192.168.1.0          D
SERVER2              192.198.1.0