1. How Online PIDKey Check Works

Every genuine 25-character Microsoft product key encodes a cryptographic Group ID (RefGroupId) and Serial Number. When you paste up to 50 product keys into our Free PIDKey Check Tool, our engine automatically matches each key against 146 official Microsoft pkeyconfig.xrm-ms digital certificates in parallel and queries Microsoft's licensing server read-only. 

Key               : XXXXX-XXXXX-XXXXX-XXXXX-XXXXX
Description       : Win 10 RTM Professional Volume:MAK
Sub type          : [TH]X19-98806
Remaining         : 482
Time              : 10/31/2026, 9:45:00 PM (GMT+5:30)

Understanding Every Line of Your Key Check Result:

  • Key: The normalized 25-character Microsoft product key (XXXXX-XXXXX-XXXXX-XXXXX-XXXXX).
  • Description: The official Microsoft product SKU name and license channel (e.g., Win 10 RTM Professional Retail, Office21ProPlus2021VL_MAK_AE, or Windows Server 2022 ServerStandard OEM:NONSLP). Note that Windows 10 and Windows 11 share the same core PKeyConfig family, so a Win 10 RTM Professional key activates both Windows 10 Pro and Windows 11 Pro!
  • Sub type: The Microsoft Part Number (X19-..., X21-..., X22-..., X23-...) and licensing build identifier.
  • Remaining / Error code: For Volume MAK and OEM keys, displays the exact live number of online activations remaining on Microsoft's server. For Retail keys (or when Check MAK Error Codes is checked), displays the live Microsoft server status code.
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2. Complete Microsoft PIDKey Error Codes Reference

When checking Retail, OEM, or Volume MAK keys with Check MAK Error Codes enabled, Microsoft's activation endpoint returns a specific hexadecimal status code:

Error Code Status Detailed Explanation & Next Step
Online / 0x0 Valid & Active The key is 100% genuine and activates directly over the internet with one click—no phone activation needed.
0xC004C008 Phone Activatable (Retail / OEM) The Retail or OEM key is genuine and NOT blocked, and can be activated using telephone activation. Install the key, get your 63-digit Installation ID via slui 4 or slmgr /dti, and convert it into a 48-digit Confirmation ID on GetCID.cc (GetCID Free).
0xC004C020 Phone Activatable (Volume MAK) The Volume MAK key is genuine and eligible for Telephone Activation! Install the key, retrieve your 63-digit Installation ID via slui 4, slmgr /dti, or ospp.vbs /dinstid, and generate your 48-digit Confirmation ID on GetCID.cc (GetCID Free).
0xC004C003 / 0xC004C060 Key Blocked Microsoft has permanently blacklisted this product key. It cannot be activated online or by phone. Replace it with a genuine key from ResellKeys.com.
0xC004C770 / 0xC004E028 Server Throttled / Busy Temporary Microsoft licensing server rate-limit or retry state. Wait a few seconds and run the check again.

3. How to Convert Windows Server Evaluation to Full Standard or Datacenter (DISM)

If you installed Windows Server 2025, 2022, 2019, or 2016 Evaluation (`ServerStandardEval` or `ServerDatacenterEval`), entering a Retail, OEM, or Volume MAK key directly in Settings or slmgr.vbs /ipk will fail with an edition mismatch error. You must first convert the Evaluation image to the full licensed edition using DISM:

Step 1: Check Your Current Windows Server Edition

Open PowerShell or Command Prompt as Administrator and run:

DISM /online /Get-CurrentEdition
DISM /online /Get-TargetEditions

Step 2: Convert Evaluation to Full ServerStandard or ServerDatacenter

After verifying your Windows Server product key in PIDKey Check, run the command below matching your target edition (replace XXXXX-XXXXX-XXXXX-XXXXX-XXXXX with your genuine key, or use the official Microsoft KMS client setup key to convert first and install your MAK/OEM key after reboot): 

REM Convert Windows Server Evaluation to Full Standard Edition:
DISM /online /Set-Edition:ServerStandard /ProductKey:XXXXX-XXXXX-XXXXX-XXXXX-XXXXX /AcceptEula

REM Convert Windows Server Evaluation to Full Datacenter Edition:
DISM /online /Set-Edition:ServerDatacenter /ProductKey:XXXXX-XXXXX-XXXXX-XXXXX-XXXXX /AcceptEula

Type Y when prompted to restart your server. Once rebooted, if your Server key requires telephone activation (0xC004C008), run slmgr.vbs /dti and paste the 63-digit Installation ID into GetCID.cc!