Users

what are you booting your os from? the hdd? or sdd?

I would be a bit suprised if windows even let you; I believe you have to have the users folder, because if a new user is added, his profile will be there. There are also likely some hidden and system files there that you don't see.

However, there are ways to do what you are trying to do. This is my personal favorite way of getting the users directory off of my SSD:
http://lifehacker.com/5467758/move-the-users-directory-...

Make sure you back things up first.
You can also use that method to move the programData folder, which is a hidden folder that holds alot of data.

THis guide has some other space saving tips:
http://thessdreview.com/ssd-guides/optimization-guides/...

Let me make a different suggestion. Moving documents, pictures, and so forth makes a great deal of sense. But there is other stuff in the /users (or /documents and settings) directory tree that is so closely tied to the OS that it should be kept with the OS. Certainly the Current User part of the registry (NTUSER.DAT in XP, I don't know off the top of my head in 7). Some of the Application Data is saved configuration and even plug-ins.

For this reason, I leave most of the users' directories in place on the OS drive and only move what is clearly data. Both approaches are perfectly valid; I'm not saying not to symlink the directory. Just offering another opinion.

You can edit the registry to point ALL current and new users to the other drive.

I use to do this.... in the end it is a bigger PITA then it is worth.