Look at your Google calendar through the Vista Calendar.

One of the greatest things you’ll find in Vista is iCal, the built-in calendar that allows you to subscribe to calendars from third-party sites such as Google and get updates from them. If you like the Vista Calendar, but you also want to receive information from other Internet sources, then this function is for you. For example, Google allows you to quickly add an event to Google Calendar, but not to the Vista calendar.

Further here:
ru.vistarewired.com/2007/04/24/%d1%81%d0%bc%d0%be%d1%82%d1%80%d0%b8%d1%82%d0%b5-%d0%bd% d0% b0-% d1% 81% d0% b2% d0% be% d0% b9-google-% d0% ba% d0% b0% d0% bb% d0% b5% d0% bd% d0% b4% d0% b0% d1% 80% d1% 8c-% d1% 87% d0% b5% d1% 80% d0% b5% d0% b7-% d0% ba% d0% b0% d0% bb