The biggest issue you should care about is drivers. 

Do 64bit drivers exist for your laptop? Check that before you do anything, as lot of hardware companies don't have any available. If you can't find Windows 7 drivers, usually the Vista drivers will work.

Ontop of that, if you are using your laptop for heavy-lifting applications that require a lot of memory, then 64bit is better. Though with 2gb of RAM it's barely going to make any difference for you, as 64bit excels because it can support more than the ~3gb limit of 32 bit windows. So the advantage is once you have more than 4gb of ram.

The heavy-lifting applications usually are 3D software: Maya, 3DS Max, or graphics applications such as Photoshop and Gimp. Also gaming on 64bit gives slightly faster framerates, though that's a product of the processor and motherboard not the operating system. Your existing games may not work on 64 bit Windows.

You are also likely to find some installers refuse to install on a 64bit version too, mostly from dumb installers looking at registry keys.

My choice would be stick with 32 bit Windows 7, as a laptop (atleast one that only has 2gb of RAM) is probably not going to be used for any of those applications, or gaming.

If you want another opinion Tomshardware has a few threads on it.

Which Windows 7 to install?
I'm kinda newbie in this Windows 2008 Server R2 configuration stuff, so I would appreciate any help regards the issue I'm facing.

After a Windows 2008 Server R2 clean install I created a couple of local user accounts and joined them to the administrators group, I tested them and I was able to log on with each one.

Then I installed Active Diectory role (DNS role implied) and runned DCPromo. The domain was created and promoted succesfully and I was able to log on into the domain from a client machine.

The issue began when I realized that I was no longer able to log on locally into the server (meaning LOCALMACHINE\localusername). I looked into domain user accounts and noticed that the local user accounts I created previously were now part of the domain. I consider a bad thing not being able to log on locally anymore, so in a shot to fix it I stopped the Active Directory service... my bad! Now I'm sort of locked up, I can't log either locally or as part of the domain.

Can someone please shed some light in this? What did I miss in the process? I tried googling but could find any straight forward solution or explanation. What concept I'm not catching?How can I promote a server to PDC and still be able to log on locally?

Thanks in advanced. 
