Get Your Confirmation ID — Windows & Office Phone Activation (India)

If online activation keeps failing — or your PC simply isn’t connected to the internet — Windows and Office both offer a reliable fallback: telephone (offline) activation. Instead of activating over the web, you get an Installation ID from your PC, exchange it for a Confirmation ID, and type that code in to finish. This guide walks through the whole process for Windows 10, Windows 11 and Office, with the exact steps and the common errors that send people here.

If you just want your Confirmation ID without the hassle, you can use our free Confirmation ID tool here — it returns your CID in seconds, no calling Microsoft.

What is a Confirmation ID, and why do you need one?

Microsoft activation can happen two ways: online (automatic, over the internet) or by phone (offline). When you choose phone activation, your computer generates a long Installation ID. You submit that ID to Microsoft’s activation system, and it returns a matching Confirmation ID (CID) — usually shown in eight blocks, labelled A to H. Entering that CID into the activation screen completes the licence. The CID is the final piece of the puzzle; without it, phone activation can’t finish.

How to activate Windows 10 and 11 by phone (SLUI 4)

Windows has a built-in command that jumps straight to the phone-activation screen:

1. Press Windows key + R to open the Run box.
2. Type slui 4 and press Enter. (There’s a space between “slui” and “4” — a common typo that makes the command fail.)
3. Pick your country or region from the dropdown and click Next.
4. Windows displays your Installation ID — a long number split into nine blocks.
5. Take that Installation ID to our Confirmation ID tool, enter it, and get your Confirmation ID instantly.
6. Back on the activation screen, click Enter Confirmation ID, type the CID into boxes A–H, and click Activate Windows.

That’s it — Windows is now permanently activated, with no internet connection required on that machine.

SLUI 3 vs SLUI 4 — what’s the difference?

People mix these up. slui 3 opens the screen where you enter or change a product key. slui 4 opens the phone-activation wizard where you get your Installation ID. If you need to put in a key first, run slui 3; then run slui 4 to activate by phone.

How to activate Microsoft Office by phone

The Office process is similar:

1. Open any Office app (Word, Excel, etc.) and enter your product key when prompted.
2. When the Activation Wizard appears, choose “I want to activate the software by telephone.”
3. Select your country. Office shows its Installation ID.
4. Enter that ID into the Confirmation ID tool to get your CID.
5. Type the CID into the A–H boxes and finish activation.

This works for the perpetual/retail versions of Office: 2016, 2019, 2021 and 2024.

Common activation errors that phone activation fixes

If you’ve hit one of these error codes, telephone activation is often the way through, because it validates the licence directly rather than relying on the online check that’s failing:

• 0xC004F074 — the Software Licensing Service reported the product could not be activated (common when the online activation servers can’t be reached).
• 0xC004C008 — the activation server determined the key can’t be used for online activation (often a “used on too many devices” signal).
• 0xC004C003 — the activation server determined the product key is blocked or in use.

Phone activation resets the activation path and frequently completes where the online route stalls. If Microsoft rejects the Installation ID itself because the key has genuinely exceeded its activation limit, though, that’s a key problem — not an activation-method problem — and you’d need a fresh licence.

Is Microsoft 365 / Office 365 included?

No. Microsoft 365 and Office 365 are subscription products that activate through your online Microsoft account. They don’t generate Installation IDs or Confirmation IDs, so phone activation doesn’t apply to them. Confirmation IDs are only for perpetual Office (2016–2024) and Windows.

Buying a genuine key (India)

If you don’t have a key yet — or your current one is the reason activation is failing — you can buy a genuine, telephone-activation key at Indian pricing and use the tool to activate it straight away:

• Windows 10 Professional — ₹199
• Windows 11 Professional — ₹219
• Office 2021 Professional Plus — ₹399
• Office 2024 Professional Plus — ₹699

Every key is genuine, billed in rupees, and comes with activation support over WhatsApp. No USD billing, no waiting on hold with Microsoft.

The fast way: get your Confirmation ID now

Skip the phone call entirely. Head to our free Confirmation ID tool, paste in your Installation ID, and get your CID in seconds. Then finish activation on your own screen — done in under a minute.