Download v1.2 (for Windows NT 4.0)


DelGuest deletes the built-in Guest account in Windows NT. This account is supposed to be impossible to delete, and it is impossible to delete through the ordinary user interface, but with DelGuest you can do it.

Usage instructions

Download the exe file and run it from the Command Prompt. It will give you the instructions you need, but please read the Q&A first.


Q: I've run DelGuest but the Guest account is still there. What's wrong?

A: It could be because you haven't rebooted the computer yet - you need to reboot it before the Guest account disappears. It could also be because you have renamed the built-in Guest account, and created another account with the name "Guest". DelGuest always finds the built-in Guest account and deletes it, regardless of the name.

Q: Is it dangerous to run DelGuest?

A: DelGuest uses a way to access the SAM database which is definately not supported by Microsoft, and it would be very difficult for me to determine that this technique can never cause corruption of the SAM database in any case. Thus, you have to be aware of the risk that DelGuest may corrupt the SAM database, which would be a very bad thing indeed. However, I have not experienced any problems at all when testing it, and it could be completely safe although it would be a lie if I claimed that I know it is. Use your own sense, and think twice before running it on a production server without thoroughly testing it first.

Q: Despite your warnings I have decided to run DelGuest on a very important server. What should I think of before I do so?

A: First of all, remember that to complete the deletion of the Guest account you must reboot the server. Second, try to minimize the access to the SAM database while DelGuest is being run. That is, do not allow other account creation/deletion at the same time, and preferably not even logons. The best thing would be to disconnect the server from the network, run DelGuest, reboot it and meanwhile reconnect it to the network again.

Q: Why in the world would anybody want to run DelGuest at all?

A: Having an enabled Guest account can be a security problem, and of course you can always disable it, but if you delete it completely there is no risk that somebody enables it by mistake.

Q: I plan to install Windows NT on a computer and then run DelGuest before installing anything on it. Then I install the software I need, and start using the server. Could this cause any problems except that DelGuest could destroy the NT installation when it is being run?

A: No, it should be completely safe after you start using the server, but you can never be completely sure of anything. I consider this the best way to use DelGuest.

Q: Why do I get the message "Error: Unable to locate the built-in Guest account."?

A: Most likely it has already been deleted by DelGuest.

Q: Why do I get the message "Error: Unable to access the SAM database."?

A: You are probably running DelGuest from an account not included in the Administrators group, which is needed.

Q: Would it be possible to delete the built-in Administrator account the same way?

A: Yes, it's possible, but it would be too dangerous to release a tool like that. For example all administrators could lock themselves out, or all accounts in the Administrator group could be deleted.

Q: When I double-click on the file a window comes up and disappears immediately. What's wrong?

A: You must run the file from a Command Prompt.

Q: I have a question that is not covered here. Where can I get help?

A: Send me your question. I can't promise that I will have time to answer, but I'll do my best.

© Arne Vidstrom. All rights reserved.