Auslogics Regdefrag works on 7048 x64.
Surprised how little defragging was needed - only 3% fragmented according to the app.
Tried it with separate System and Boot partitions and with the Boot partition also set as System .
No problem with either.
I used the earlier free version v220.127.116.115.
Sadly, it is no longer free - trial version available. Auslogics Products
Also tried with the free Glary regdefrag and Quicksys regdefrag - neither work with 7, though both work well with Vista.