Leave FTP aside for now. You can always upload the sitemap yourself
after GSC has generated it.
With Vista there are many extra security/privacy issues which you have
to tame.
For one thing the GSC program has to be run as adminstrator in Vista.
It also seems that your Vista has suatained an update. Or maybe other
software you have (e.g. Spypot, Kaspersky ) have been upgraded and
now their settings are stricter. In that case you need to check
through settings to see what they block.
Try this first and lets 'see if you still have problems and which
ones.