BaseCamp 4.2.4 will not load

Windows XP SP3 & BaseCamp 4.2.2. After accepting the EULA, the loading bar shows about 2/3 complete then a error box appears: The feature is on a network resource that is unavailable. BCMAIN.msi is in the folder listed, same error is always given. When I cancel & exit, sometimes a message is displayed to contact support as the old version of BaseCamp cannot be deleted. Add/Remove Programs lists BaseCamp, but does not give the option to remove.