If your windows vista runs very slow I mean it takes time to open even my computer and other folders. then you can do the following things ---
1) make sure that there are less files in the folder if there are many then you pack them in folder.
2) you should have some space free in the hard disk 10% at least.
3) run de-fragmentor as it helps hard disk run faster.
4) one trick to make explorer run faster is that you set the priority of explorer process to high click here to know how to do that.