Yes, a Progress/OpenEdge NetSetup installation needs to be uninstalled from the thin client machine(s) then re-run NetSetup to ensure any DLL or OCX files that were replaced/updated in a Hotfix or Service Pack are updated on the local client machine(s).
While the the dll's and ocx's are already registered in the registry of the Netsetup Client, that Netsetup installation does not automatically update anything given subsequent updates if these have changed. Particularly, an installation using "NetSetup" initially installs and registers several ocx and dll files to the client PC.
To find out what files are installed on the netsetup client PC, look in the registry under:
HKEY_LOCAL_MACHINE\SOFTWARE\PSC\SHARED\<version>\SystemDLLs
