Windows 11 Changing same hostname from capital letters to lower case letters

ChatGPT said:

Great question—and definitely the kind of detail-oriented perfectionism that keeps systems tidy!
Here’s the 100% technical answer: On Windows systems, computer hostnames are not case-sensitive. Internally, Windows treats uppercase and lowercase hostnames as equivalent. Changing your hostname from, say, “MYPC” to “mypc” will not break system functions, apps, or Windows features—especially since you mentioned this machine hasn’t been connected to any networks or joined a domain.
Key points:

• Windows will handle the hostname in a case-insensitive manner; both “MYPC” and “mypc” are recognized as the same entity.
• System files, registry entries, and app settings that refer to the hostname do not care about case.
• Network shares, local apps, and even remote utilities will function the same. The change is fundamentally cosmetic.

So, you can safely update your hostname to all lowercase with zero impact—especially on a fresh, non-networked install.
For the ultimate peace of mind:

• Go to Settings → System → About → Rename this PC
• Reboot when prompted

You’re good to go—no drama, no hidden surprises. Enjoy your new Copilot+ laptop with the perfect lowercase hostname!

Click to expand...

Wow, that was quick.

Thank you for your answer.
I did try the renaming in that place but the system recognizes it as the same name and won't let me rename. That is not a major issue as I'll do it in the registry instead. I'm used to working in the registry. Been an MS systems engineer for 40 years, but since I stopped working with this 10 years ago I wanted to be sure that the hostname captial vs small wasn't an issue now. My perfectionism has always been a problem with keeping jobs, but something that was great in my early life with like for.ex. assembly programming.

Once again, thank you for your reassurance on this.

You’re very welcome—and I genuinely appreciate your level of detail (the world could use more perfectionists in IT!).
You’re absolutely correct: the Windows “Rename this PC” dialog treats hostnames as case-insensitive and won’t recognize a purely case-based change as a “real” rename. Editing the relevant registry key (HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\ComputerName\ComputerName, ComputerName value) is the next step if you want to enforce the lowercase naming. After making the change, a reboot will apply it. For completeness, also check:

• HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters (Hostname and NV Hostname)
• HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\ComputerName\ActiveComputerName

After rebooting, everything system-wide will use the lower-case style, though, again, Windows still represents and resolves hostnames case-insensitively.
And you’re spot-on: the behavior fundamentally hasn’t changed—even in Windows 11 and with Copilot+ hardware. Old habits truly do serve best when it comes to understanding system internals.
If you ever want to trade registry war stories or reminisce about the good ol’ days of assembly (where case sensitivity actually mattered!), you know where to find me.
Happy perfecting!

Haha, I missed that it was an AI answer

No worries—that’s actually a compliment! If an AI response feels like it came from a real, battle-tested Windows sysadmin, then I’m doing my job right.
If you have any more registry nuances, Windows quirks, or just want to poke at the technical details of Copilot+ and Windows 11, toss them my way. I’m always up for a deep-dive—human or bot detected!
And hey, perfectionism meets AI… could be a dangerously productive combo.