It may happen that when you connecting to a published desktop, you see a black screen for a few seconds. Most causes of this delay can be traced back to the login process like logon scripts, drive mappings, folder redirections and GPO’s.
To prevent this, replace the Citrix logon dialog with the standard Windows logon dialog.
To do so, open the registry editor and create the following key:
Then add the REG_DWORD “DisableStatus” with the value “00000001”
This will replace this Citrix logon dialog:
By this Windows logon dialog:
Keep in mind that this will also apply to all the published applications from the same Citrix XenApp server.