Well, first of all be very careful about which drive you are looking at. When you removed the old drive and inserted a new one, it was probably not listed as primary in the bios, but one of the other drives was.
Did you install Windows first and then try to image? If you did install Windows 7 first, you may have part of the boot files on another drive.
I would disconnect the unnecessary drive, make sure the new drive is listed first in the bios, then boot to the Windows 7 install DVD. On the second page, there is a Repair My Computer option that will lead to the image restore. The restore will make the partitions just like the original drive, so hopefully the new drive is large enough.
You did not give many specifics about how far you got in the re-image process, but does it see the image on the other drive, if it gets that far?
Are you using another install media beside the Windows 7 DVD, possibly a manufacturers version?