I'm using Win 7 64 Bit on my new pc. I've got Office 2007 with Outlook and it is crap. I will be moving back to Mozilla Thunderbird, but you have to use a 32 bit client as there is no 64 bit client yet.

I've used Thunderbird for years and I think it is the best email program around. Your ISP should have a guide on their support page to configure your email client.