Well, I think that some more information about the context is needed.
What kind of installation method are you using (silent/interactive)? What OS?
You say you removed previous installation with BES Remover, but as the installer thinks something of BESClient is still around, are you sure nothing has been locked by some kind of usage (memory or multiple users? normally it is not required, but was a reboot done?). Other bigfix components on the same system?
Maybe some more information is available from the installer log: what information is available before the error line?