The simplest thing I can think of (apart from a fresh install with a Windows 7 installer DVD), is this:
- do a factory reset on your original hard disk (but don't forget to backup your data, then!)
- use a bootable CD/USB disk imaging software, like Norton Ghost, or Acronis True Image, to create an image of the system partition. You'll need some big ass USB pendrive to put the data on, I believe... or an USB drive... I'm not sure, maybe they can write to DVD too novadays?
- and use the same software to restore that image to the new SSD
I did something like this long ago, but I remember that restoring to a smaller partition wasn't a problem as long as the data had enough space.