I hit upon a simple solution to the View Agent install error #28030. Specifically, I used local admin account to launch the installer, which worked. Windows XP SP2 - added to domain.
This action resolved two issues I have been encountered when installing View Agent:
1) ThinPrint Install Error: "You do not have permission to modify the settings for this printer..."
2) USB Hub and USB Device drivers: "Error 28030. The Installer failed to install the USB driver."
Frankly, I do not know specifically which policy is keeping me from installing the drivers when I log in as a domain user/administrator. I strongly suspected the
local policy "load and unload device driver" - particularly because this was disabled whenever I was logged in as a domain user. This included Domain Admin user.
Incidentally, I tried to push down these rights from within AD. (Domain controller: Domain Security Policy | + Local Policies | User Rights Assignment | Load and Unload Device Drivers).
I then used GPUDPDATE.EXE /FORCE, and although the local policy changed, the install still failed for both print & USB.
The agent services & devices seem healthy when I log in as a domain user. So, I was able to move forward. Incidentally, this only led me to my next challenge... when I add desktop to an individual pool, the machine is not fully accessible. It's likely that my problem is unrelated to the view agent install workaround. I add this for completeness, only.
For enquiring minds, my situation is that the individual desktop is created in view manager, however, under desktop sources, status is "waiting for agent." This happens with more than one guest OS. As I said, I think this is unrelated to USB Driver Installation difficulties.