I'm doing this same thing except that I want to keep the memory on my HDD. Lol!
My HDD has some files I'd like to copy over to my SSD before I wipe my HDD clean.
After the transfer, I'll wipe it and use it as a secondary storage device.
So here's my plan...
1. Plug up the SSD, boot Windows-7 onto it.
2. Turn off PC, unplug PC, plug up HDD, plug up PC, turn on PC.
3. Success! I can now access my HDD as a secondary hard drive (by opening My Computer) even though my HDD has Windows-XP on it. I can transfer files from it, which I will do.
set your SSD as your main boot device in your BIOS (you will need to have both SSD and Hard Drive plugged in to do this) then you boot into your SDD and the hard drive would show up and a second disk drive in my computer. From there you navigate find an copy your files to your SSD and then wipe your hard drive