[Minecraft 1.7.2] [Windows Vista] [Can't Join] *HELP!*

So I, as many Minecrafters out there were, was very excited to get going when 1.7.2 came out. However, a lot of my favorite servers were still on 1.6, so I didn't update right away.

However, I have now created a new profile with the release 1.7.2 version. I can log in with that profile just fine. However, when I get to the main screen where it asks if I want single our multiplayer, there is a message saying that I have an old graphics card and I won't be able to play in the FAR FUTURE. I can then easily access the single or multiplayer menus where I choose a server or world. But if I try to join either one of those I get a black screen with the faded outline of my inventory items. My MC then is frozen and I cant move or anything. I have to resort to doing CTRL+ALT+DEL to force quit my MC.
However, if I play on 1.6.4 I can join any 1.6.4 server easily or any single player world. So I would very much appreciate any help on this. Thanks!

Notes:
Computer: Windows Vista Home Premium (Usually very minimal lag)
32-bit operating system
Processor: Intel Core 2 duo CPU