It's probably for the best, if you're going to replace your boot drive it's usually best to start totally from scratch with a fresh install using your install disc and activating with its key rather than cloning an existing OS.
Tips:
Download and save out the required drivers, either to disc or a flash drive: Motherboard sound/chipset/lan, video etc, taking the latest WHQL drivers from the relevant manufacturers websites, that way they'll be available once Windows has finished installing and the system will have a fully updated driver set installed.
Don't forget to save out your Internet Favourites!
SSDs like to be formatted in AHCI mode, make sure your BIOS is set to do so and also if the existing HDD was not formatted with AHCI active, you'll have to reformat it, AHCI and non AHCI drives are not usually compatible!
Remember. Win7 is a very mature OS, it'll take some time for it to fully update itself.
A fair number of current games (and many Steam games) save to the Cloud, you might not lose as much as you fear.
You WILL lose music/video/work files if they're not backed up to either DVD or flash drive-and if the HDD was not formatted under AHCI you'll need to use another system to recover them.