Is C: sacred?

"C:" is not supposed to be special any more, though once upon a time it was. When hard disks were first added to personal computers A: and B: were assigned to the floppy drives, and C: was the hard drive. In fact, C: could be counted on to be the hard drive, the boot drive, and the drive containing the operating system.

But it's been quite a while since that was a valid assumption. As you've seen today other drive letters can now end up as the boot/Windows drive, and things pretty much work.

The risk, of course, is some software making an incorrect assumption that C: is the Windows drive. Fortunately those situations seem to be infrequent, and getting more so.

Advice #1: If it ain't broke... don't fix it. As we'll see in a moment fixing this gets painful. Things should work just fine with the setup you have. You may have a mental hurdle to overcome in remembering that C: isn't the boot drive (I know I would), but unless you run into a problem that can be traced to the drive assignments, I wouldn't change a thing.

Advice #2: Pseudo-standards are good. When you build out a new machine I do recommend, if you can, making sure that you end up with a system that has its boot drive as C:. As I said, it shouldn't be necessary, and it's not really a "standard", per se. But it is one of those things that can make life a little easier in case you do run into situations where some software makes a bad assumption. Given that 99% of the machines out there are configured this way, it's just a safer thing to do.

Sad Reality #1: Change is painful. Changing drive letters is easy - as long as you're not talking about the drive that holds Windows. In my opinion the only safe way to change the letter assigned to your Windows drive is to reinstall Windows.

Here's the problem: installed software, including Windows itself, will have been configured to whatever the Windows drive was when they were installed. Using your example, by that I mean that in various configuration files including but certainly not limited to the registry will be references to F:. Lots and lots of references to F:. Unfortunately changing the drive's letter assignment won't go through and find and change all those references to the old configuration.

If you do successfully change F: to C:, then a lot of things are likely to stop working. In fact, I'd actually be shocked if the system even booted.

Now, one could argue that you could just scan the registry for all references to F:, change them to C:, and be on your way. It wouldn't surprise me if there were tools out there that do this for you. And it might even work in many cases. The problem is that frequently the registry is not the only place information is stored. Let's say that some random application you use is configured not to use the registry and stores its own configuration data itself, in a proprietary format. You may be able to fix it when you run the application, but you may not. And it's an annoyance in any case.

That's why I say that the safest way to reassign drive letters involving the Windows drive is to reinstall. That way everything is configured properly from the start.

I'd love to hear some reader's experiences on this topic. As you can tell, reassigning the Windows drive letter is something I actively avoid.