http://www.terabyteunlimited.com/dow...generation.htm
It's free for 30 days. No restrictions.
Put both drives in at the same time, use the tool to clone the old HD over, then you can get rid of the 2nd drive out of the system.
I have not used the current version, but used an older version for ages - it's brilliant, plus if you're in to running different OS at the same time, it's a great partition manager.
I used to use it to build up a "clean" config on a machine, then backup the entire clean install to DVD(s), then if you ever had to, you could use it to make a "fresh" install. Less of an issue in the days of Vista, but I always had a "clean" XP install (including every driver for the motherboard etc) ready to go when things got too unstable for my liking.
If you like it, it's cheap too. I particularly liked it because you could install it off a single floppy drive. It's a really powerful tool.