I finally figured out how to silently install UVNC server on XP Pro and Win 7. This seems to work fine on XP, but to make it work on Win 7, you'll need to add "winvnc.exe" to the "allow" list for Windows Firewall.
If you know of the other parameters and values I can use for the INF file, please feel free to share.
I'm not using Windows registry. All configurations are in the INI file which I've previously created after making all the changes I want to UNVC Server on another computer. I simply copy that INI file to another computer when the script runs (see below).
if not exist "C:\Program Files\UltraVNC" md "C:\Program Files\UltraVNC"
copy "C:\App Deploy\ultravnc.ini" "C:\Program Files\UltraVNC\ultravnc.ini" /Y
"C:\App Deploy\UltraVNC_184.108.40.206_Setup.exe" /verysilent /loadinf="uvncinstall.inf" /log