Error: 1605

The specified product key is not valid for the target edition.

Run this command again with a product key specific to the target edition.

You might get the above error, When you activate the Windows Server Evaluation with your retail keys by these commands :

DISM /Online /Set-Edition:ServerStandard /ProductKey:xxxxx-xxxxx-xxxxx-xxxxx-xxxxx /AcceptEula

DISM /Online /Set-Edition:ServerDatacenter /ProductKey:xxxxx-xxxxx-xxxxx-xxxxx-xxxxx /AcceptEula

How to Fix The Error 1605 for Windows Server ?

Please run these commands above with the gerneric KMS Client Product Keys in the list below, then you will successfully upgrade to the Standard, or Datacenter edition ! 

But it will only help you to convert the evaluation edition to Standard,or Datacenter edition, it wont help you to activate it , you still need to run these command to activate the Windows Server with your Retail Windows Server key:

slmgr /upk

slmgr -ipk xxxxx-xxxxx-xxxxx-xxxxx-xxxxx

slmgr/ato

If you still do not have a retail Windows Server product key , you can try to get one from the legit reseller keyingo.com

Here is the Generic KMS Client Product Keys for all Windows Server Edition

Windows Server 2022 KMS Client Product Key

Windows Server 2022 Datacenter: WX4NM-KYWYW-QJJR4-XV3QB-6VM33

Windows Server 2022 Standard: VDYBN-27WPP-V4HQT-9VMD4-VMK7H

Windows Server 2019 KMS Client Product Key

Windows Server 2019 Datacenter WMDGN-G9PQG-XVVXX-R3X43-63DFG

Windows Server 2019 Standard N69G4-B89J2-4G8F4-WWYCC-J464C

Windows Server 2019 Essentials WVDHN-86M7X-466P6-VHXV7-YY726

Windows Server 2016 KMS Client Product Key

Windows Server 2016 Datacenter CB7KF-BWN84-R7R2Y-793K2-8XDDG

Windows Server 2016 Standard WC2BQ-8NRM3-FDDYY-2BFGV-KHKQY

Windows Server 2016 Essentials JCKRF-N37P4-C2D82-9YXRT-4M63B

Windows Server 2012 R2 KMS Client Product Key

Windows Server 2012 R2 Standard D2N9P-3P6X9-2R39C-7RTCD-MDVJX

Windows Server 2012 R2 Datacenter W3GGN-FT8W3-Y4M27-J84CP-Q3VJ9

Windows Server 2012 R2 Essentials KNC87-3J2TX-XB4WP-VCPJV-M4FWM

Windows Server 2012 KMS Client Product Key

Windows Server 2012 Standard XC9B7-NBPP2-83J2H-RHMBY-92BT4

Windows Server 2012 Datacenter 48HP8-DN98B-MYWDG-T2DCC-8W83P

Windows Server 2008 R2 KMS Client Product Key

Windows Server 2008 R2 Standard YC6KT-GKW9T-YTKYR-T4X34-R7VHC

Windows Server 2008 R2 Enterprise 489J6-VHDMP-X63PK-3K798-CPX3Y

Windows Server 2008 R2 Datacenter 74YFP-3QFB3-KQT8W-PMXWJ-7M648

Windows Server 2008 KMS Client Product Key

Windows Server 2008 Standard TM24T-X9RMF-VWXK6-X8JC9-BFGM2

Windows Server 2008 Enterprise YQGMW-MPWTJ-34KDK-48M3W-X4Q6V

Windows Server 2008 Datacenter 7M67G-PC374-GR742-YH8V4-TCBY3