I don't believe that you can do so with just windows. Now if you have another program, like Norton GoBack, or whatever, then you can. But just with Windows, I do not believe that such a thing is possible.
If you are not looking into deleting certain specific restore points, you can use Disk Cleanup to delete the most recent ones.
START>PROGRAMS>ACCESSORIES>SYSTEM TOOLS>
Disk Cleanup.
Go to "More Options" tab. Look for the system restore button. Should be the last one. There are three.