Endpoint 12.1 RU2 Client Will Not Install

I am trying to install Endpoint Protection Client v12.1 RU2 32-bit on Windows XP SP3 and it will not install.  When I run the install program, the hard disk thrashes for a minute and then nothing.  There are no logs created in the Event log or the SEP Install log.  I have run the SymHelp application and it says my computer meets requirements for installing 12.1 local install.  I uninstalled all previous versions of Endpoint with no luck.  I do not know what else to do.