Thank you [email protected]. Fake keys are quite complicated to detect.

[email protected]
This key can checked by PID Checker tools v1.5.4 as a "Fake key"

Key: 8N7V6-V34GC-MRMF4-VP2T8-33VQQ
Description: Win 8.1 RTM Professional;ProfessionalN;Enterprise;EnterpriseN Volume:MAK
Sub Type: [Blue]X18-95515
Activation Count: 500
Error Code: Fake Key
Time: 20:28:23 26/06/2025 (GMT+7)


But these keys are some example of fake keys that passed PID Checker tools (even in fake keys mode);
9TB3H-3N8WP-WTRF8-PP9YK-DYKV7
H84PN-BB8RC-JPXHP-MV334-BY74H
HVT8D-8N4JG-7MHPC-X7XBB-BBKV7
NC93D-Q4379-VGHMX-HMMYR-6Q9V7
NPB4H-XPGR2-9HKQR-MKRCP-CKFFH
NR4K4-FH4WF-X7H28-FMMVP-V8T77
VJNRQ-CYD9C-P9WQ4-Q746Q-JT3H7
GBNHB-B2G3Q-G42YB-3MFC2-7CJCX


PID Checker tools check result (Error Code: Unsupported); 
Key: 9TB3H-3N8WP-WTRF8-PP9YK-DYKV7
Description: Win 10 RTM IoTEnterpriseS OEM:NONSLP
Sub Type: [Vb]res-v4365
Activation Count: 20
Error Code: Unsupported
Time: 20:41:16 26/06/2025 (GMT+7)

PID Checker tools check result (Error Code: Nothing); 
Key: GBNHB-B2G3Q-G42YB-3MFC2-7CJCX
Description: Office24_VisioPro2024VL_MAK_AE
Sub Type: X23-57891
Activation Count: 100
Error Code: 
Time: 21:15:40 26/06/2025 (GMT+7)


Another tools check result;
ProductKey:9TB3H-3N8WP-WTRF8-PP9YK-DYKV7
Description:Win 10 RTM IoTEnterpriseS 2021 OEM:NONSLP
ErrorCode:0xC004C004
CheckedTime:2025-06-26 20:38:32 PM (UTC+07:00)
IIID:3830826-4023650-7286145-7812926-8594065-8285250-8772152-3928206-9746964
Key blocked!

Another tools check result;
ProductKey:GBNHB-B2G3Q-G42YB-3MFC2-7CJCX
Description:Office24_VisioPro2024VL_MAK_AE
ActivationCount:100
ErrorCode:0xC004C004
CheckedTime:2025-06-26 21:17:00 PM(UTC+07:00)
IIID:4495162-4463513-9136395-6995581-5487700-1864292-6011683-9161823-7552080
Key blocked!

Administrator
Admin, please update PID Checker tools. Thank you!

[email protected] 
I answered you in a private message.

Yes, I know, I just give an example of fake key that passed the PID tool. 
How to check Fake keys correctly like your result [email protected]? 

 [email protected]
ProductKey:8N7V6-V34GC-MRMF4-VP2T8-33VQQ
Description:Win 8.1 RTM Professional;ProfessionalN;Enterprise;EnterpriseN Volume:MAK
Remain:500
ErrorCode:0xC004C004 Fake key
CheckedTime:2025-06-26 15:35:12 PM(UTC+04:00)

Of course, it is here

Key: 8N7V6-V34GC-MRMF4-VP2T8-33VQQ

Description: Win 8.1 RTM Professional;ProfessionalN;Enterprise;EnterpriseN Volume:MAK

Sub Type: [Blue]X18-95515

Activation Count: 500

Time: 08:37:08 26/06/2025 (GMT+7)

Can you send me a sample for the fake key?

Thanks Admin. I know that PID tool on our website can detect fake keys, but some keys still pass this verification step. Some guys  [email protected]·[email protected] can check fake keys faster and better, and I wonder how they to do that without our website?

You can use our PID Checker tools, it has detect fake keys mode.