We've identified and fixed the problems some of you were seeing installing the Kobo Reader update on Windows Vista 64-bit.
Here's a link to our support forums showing detailed steps on how to get your install working on Vista/64:
http://kobo.zendesk.com/entries/2075...ice-to-upgrade
We've fixed the version of the application on our servers, so anyone who hasn't tried to upgrade yet should be fine - but if you're concerned, re-install Kobo from the link in the email we originally sent you