Cyril,
Wow, that is kind of a corner case--I quit trying to use Windows Server 2008 R2 on my workstations because the Desktop user rolls were troublesome and stayed with 64-bit Windows 7.
But thank you for posting the link suggesting to adjust the TSMSI key, glad you were able to find it.
HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows NT\Terminal Services\TSAppSrv\TSMSI\Enable
That tweak should should help for any RDP or Citrix VM users. Had the folks at Aquaveo been of help? Usually they are spot on with their tech support.
Stuart