I usually put vista in hibernation mode. (the system uptime is usually like a couple weeks
When you want to turn off your computer, don't put it into hibernation mode as this will save and write all the data to the hd. You can even remove power form the system i.e the battery or remove the power cord. Then when I need windows again, I just turn it on as normal, it will resume form hibernation, log in and everything is as I left it. I wouldn't recommend games or anything intensive however but text documents and the like are still there.
You might want to configure the back up software to be on demand or something.