The McAfee I have installed now is an official and registered McAfee installation provided for free via my ISP
www.xs4all.nl. They have an agreement with McAfee but no service. When I call for upgrade/extension I get re-directed to xs4all. No other logo's.
I can't recall if the copy (30-day free trial) which was installed by Dell had a Dell logo or not, but I would not expect so. After removing this one (including all the extra work-arounds) any installation (30-day trial downloaded from McAfee and Full version via ISP) was resulting in the 3 errors.
Only after the crash, HDD formatting and installing a virgin Vista Dell OEM problems did not occur.