Many thanks for taking the time to write that detailed post, good news... success!
I didn't do any of the procedures you detailed, firstly I decided to uninstall (again x 6) what I had installed, I noticed (as you mentioned) there was still a PSS directory still on m C drive with "skins", so I manually deleted it, I then disabled the UAC within User Accounts under Control Panel, rebooted, re-installed the ver 4.04 software and hey presto, the login screen appeared with admin/admin already populated, click OK and I was in
So if anyone wished to install PSS on a vista machine turn off "UAC" first
Thanks again, many more questions to ask on other topics as just new to CCTV