Buying a new computer can be fun, until you have to slog through migrating all your old apps, preferences, and files. Wouldn’t it be easier if you could just pop your old hard drive into the new PC and pick up where you left off? It’s technically possible, though it comes with some caveats.
With Windows 7, this was less tenable; it introduced driver conflicts, especially with lower-level hardware like your hard drive’s SATA controller. As a result, you’d often see a blue screen as soon as the computer booted, preventing you from even getting to the desktop.
Microsoft’s sysprep tool could sometimes help with this, but it wasn’t really meant for this purpose, and it came with many of its own caveats. You were almost always better off doing a clean install.
Windows 8 and 10, on the other hand, are much better about handling these conflicts. When you throw an existing Windows installation at a new PC, it’ll perform its first-time setup as if it were a new computer, grab drivers for your new hardware, and hopefully drop you onto the desktop without too much trouble.
You’ll have to do a few things yourself, but overall, it should work—I moved my drive from an AMD-based machine to an Intel/Nvidia machine with barely a hiccup. Windows Update was even able to download new patches.
That’s not to say you won’t run into any problems. This could all vary from PC to PC, and you never know what driver conflicts or performance issues may lay underneath the surface of a seemingly fine setup.
All told, I would still recommend doing a clean install if you’re migrating permanently to a new machine, but if you need something quick and dirty—like if your old PC dies and you need to access some data from your old installation—this should work well enough.