If the WD is involved you can use their excellent free Acronis cloning/imaging app to clone the old Windows 7 partition to the new SSD after initiating it in Disk Mgmt: WD Support
If this fails or isn't optimal you can try another free imaging app like Windows 7, Paragon, or Macrium Reflect. Acronis is probably better however, with more options to change size while reimaging, etc.
If these options all fail or performance isn't optimal then you can clean reinstall with the factory Recovery disks although they will restore all of the bloatware. If you have access to a Windows 7 installer, consider a superior clean reinstall using these tips to get a perfect install: re-install windows 7