Want to use old SSD in new desktop; how to migrate OS/Files?

Hi all,
I am about to complete my first-ever custom PC build in a few weeks. I am currently working on my 5-year old Dell Laptop, and what I want to do is simply run the same OS that I have installed on my SSD (Windows 7 Home x64) on my new desktop PC. I also want to retain my files/programs.

I just attempted to do this same thing with my brother's computer (i.g., using old SSD in new-hardware computer) and found out it's not as simple as Plug-N'n-Play. I ended up having to wipe his old drive and do a clean install with new OS to get it running, which was ok because it was a small-sized drive (60GB SSD), and he didn't have many files on it.

I, on the other hand, have a 500GB drive with many files I do not want to lose. So my question is:
Is there an approach that has worked for anyone to transition one's old drive to a new system? To be clear, I will be using my current laptop's SSD in the new computer as the primary OS/drive.

I have already backed up my system using Windows Backup. If I did have to do a clean install (b/c of new hardware), could I use Windows Restore to restore (at least) my files/programs of my old (current) computer? Just a thought.

Any thoughts are much appreciated as I attempt to transition with as little hassle as possible! thanks :)

You can use a flexible imaging program like Macrium Imaging to recover the image to your new build's HD, then Adjust Win7 to boot on new hardware with Paragon Adaptive Restore CD.

You'll have to re-activate with an unused retail Windows 7 license for the same version if you're using one now that came preinstalled on the Dell as that license cannot be moved.