How to app unlock your HTC S621 Windows Mobile Smartphone

This tutorial will guide you in “app unlocking” your HTC S621. I was hoping to create something like ‘how to app unlock a windows mobile smartphone’, but after spending hours and hours trying to unlock my phone, I’ve discovered there are possibly hundreds of different ways – no two are the same, and not all will work for all phones. I can only confirm that the following method works for Rogers (a Canadian mobile provider) customers using the HTC S621. It may work for other Smartphones as well.

App unlocking will allow you to install “unsigned” 3rd party software. If you’ve ever received the error “Installation was unsuccessful. The program or setting cannot be installed because it is not digitally signed with a trusted certificate”, this tutorial is for you.

installation was unsuccessful the program or setting cannot be installed because it is not digitally signed with a trusted certificate

You’ll need to download these 2 files – and regeditSTG2.exe.

  1. Upload to your device (or download it directly to your device). Save the file on your devices main memory, not on a mini-SD card. Use the file manager to navigate to and run it. Click Done when it’s done.
  2. app unlock your htc S621 smartphone

  3. Now upload regeditSTG2.exe to your HTC. Use the file manager to navigate to regeditSTG2.exe and run it.
  4. app unlock your htc S621 smartphone

  5. Now from inside the registry editor, navigate to HKEY_LOCAL_MACHINE\Security\Policies\Policies
  6. app unlock your htc S621 smartphone

  7. When you get to the second Policies folder, click the Values button.
  8. app unlock your htc S621 smartphone

  9. Highlight the 00001001 entry and then select it.
  10. app unlock your htc S621 smartphone

  11. Change the Value data: from 2 to 1, and then click Done.
  12. app unlock your htc S621 smartphone

  13. Now highlight the 00001005 entry and then select it.
  14. app unlock your htc S621 smartphone

  15. Change the Value data: from 16 to 40, and then click Done.
  16. app unlock your htc S621 smartphone

  17. Now scroll down to the 00001017 entry, highlight it and then select it.
  18. app unlock your htc S621 smartphone

  19. The Value data: may already be set to 144. If it is, leave it alone (just click Done). If it’s not, set it to 144 – then click Done.
  20. app unlock your htc S621 smartphone

  21. Now you can close down the registry editor and reboot your phone (turn the power off, then back on again). Your HTC S621 is now app unlocked and ready to install unsigned software.
{ 38 comments… add one }
  • Jose Carvalho October 11, 2007, 1:25 pm


    Great tutorial. I thought I had the same problem on my HTCS621 and I did the same thing. But the message I keep getting is “this installation file is not appropriate for this device”.
    I have been unable to install any 3rd party software on my smartphone.
    Do you have any idea on how I can fix it?


  • Chris May 3, 2008, 2:58 pm

    Hey, I’ve done all you’ve said to do, but I am still unable to install pnester. Still get the the program is not intended for this device message.

  • Ross McKillop May 3, 2008, 3:16 pm


    Exactly the same phone? HTC S621? Which version of Windows Mobile (5, 6 or 6.1)?


  • Chris May 4, 2008, 8:29 am

    Yes, the exact same phone running windows mobile 6.0. I recently retried it though and it worked perfectly. I guess I made a mistake along the way the first few times. Thanks again!

  • ELIAS A.A.JUNIOR June 24, 2008, 12:02 pm


  • jaime September 19, 2008, 3:17 pm

    how can i unlock my htc s621? i bought it in mexico is telcel,but now i have a t-mobile

  • brb December 30, 2008, 9:31 pm

    Thanks for the information, very useful!

  • Chris (A different one) January 5, 2009, 7:17 pm

    Ross – Thanks a bundle. I’d been pulling my hair out trying to figure out why I couldn’t change the registry values myself.

  • Robson February 21, 2009, 11:39 am

    Gostaria de saber, como faço para desbloquear meu HTC s 711.
    Tenho o código que a Vivo me passou, mas o aparelho não aceita.

  • Dom Marinelli March 18, 2009, 5:02 am

    This worked perfect for me on my Fuze ……This was a great help thank-you!!!!

  • Michael from Canada April 12, 2009, 6:31 am

    It worked ! Thank you !

  • Luis April 18, 2009, 8:40 pm

    Mi HTC s621 tiene código de acceso, pero en mi familia lo manipularon y ahora esta bloqueado y no puedo desbloquearlo, necesito saber si alguien me puede decir que hacer para desbloquearlo. Me urge acceder a mis contactos.

  • Evan June 3, 2009, 2:04 pm

    I have Moto Q9c with Sprint. was running mobile 6.1 but got bored with “Sliding Panel” homescreen and have been trying to do all sorts of different reg edits and cab downloading, and transfering…….
    THE Q9c will work with this interface?
    and what is the best known app unlock process for Q9c(proven please!)
    i just master reset anyways so i will try said method(great instructions) unlock method witch did not work in the most recent attempt to try a different possible interface… NOBODY seems to have a lot to say about the q9c specifically!

  • Luciano November 1, 2009, 3:10 am

    Ola amigos tenho um HTC 4550 como faco para achar um aplicativo para tv aberta ou pela intenet.


  • victorh November 11, 2009, 2:31 pm

    quisiera saber como desbloqueo el sim cada vez que coloco un sim de cualquier operador celular me pide el codigo de sim

  • lazaro December 14, 2009, 4:26 pm

    meu aparelho deu pau so fica com a tela travada no windows mobile como eu posso destravar ele por favor me ajude se poder muito obrigado pela sua atencao

  • Ahmed Essam December 29, 2009, 7:51 am

    hey dude i tried that on my htc tytn ii but it didnt work do i have to set the values back as it was or is it ok

  • alessandra January 27, 2010, 8:12 pm

    oi,ganhei um htc s621 e coloquei uma senha pessoal de bloqueio,so que errei a senha e fiz varias tentativas,não consigo desbloquea-lo,gostaria de saber se tem alguma senha original,ou tenho que leva-lo na assistencia?

    aguardo resposta..

  • cicero mariano silva February 4, 2010, 1:13 pm

    nao consigo ver o video completo no s621 o q fazer como conceguir novos programas para ele

  • Bruno April 24, 2010, 1:25 pm

    pow to aki me acabando pra baixar o windows mobile 6 no meu htc s621 . ele ja tem o 5 e nao consigo atualiza ele de jeito nunhum . se vc poder me dar uma força .obrigado desde entao

  • miruthanka April 27, 2010, 6:51 am

    Nice psot

  • yakwe June 28, 2010, 10:38 am

    comment deverouiller mon telephone htc windows mobile

  • rodriguesdem December 9, 2010, 11:30 am

    It works to HTC TYTN II perfectely.

  • kp January 21, 2012, 6:50 pm

    didn’t work on my htc p3452
    Please help me to app unlock my phone.
    I’ll be really thankful to you.

  • dm March 18, 2012, 12:32 pm

    which is the website where i can download softwares for my htc s621.

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