Welcome to the Boot Blocker Home Page

BootBlocker Info

BootBlocker was written to give some protection from unauthorised use of your Mac. It is a Control Panel which contains INIT code that requests a password before it will allow your machine to startup or 'boot', hence the name BootBlocker.

Anyone familiar with System 7 or later will already be thinking they can bypass this easily by holding the Shift key down during startup. They would be wrong !! BootBlocker has a facility to disable the shift key during Startup, this option can be turned on or off in the Control Panel part of the program.

BootBlocker is not the ultimate in security software and can be bypassed by somebody with a reasonable Mac knowledge. It will stop casual snoopers. If you need heavy security get Empower or some other commercial product.


System 7, 8 , 9.x
Open the Extensions folder which is in the System folder and put BootBlocker in there. Then select it and make an alias, place the alias in the Control Panels folder (which is also in the System folder .
If you drag BootBlocker over the System Folder icon, System 7 will put BootBlocker into the Control Panels folder automatically. It will work fine from this location but you will have to wait until all of the Extensions have loaded before you are asked for the password.

System 6
Put BootBlocker in the System Folder.

Both Systems
Select Control Panel(s) from the Apple Menu then open BootBlocker, then click the Set Password button, enter the old password, the default is PASSWORD in uppercase, then enter a new password, you will be asked to verify it by typing it again.


Open the BootBlocker Control Panel there are two check boxes one says ' Sound alarm after 3 failures ' the other says ' Disable Shift Key ' . If you check Sound alarm BootBlocker will sound a continuous alarm after 3 failed login attempts. The alarm can only be silenced by clicking the Shutdown button in the alert that is displayed. If this option is not selected then a shutdown alert is displayed after three failed login attempts.
The ' Disable Shift Key ' option is only available to System 7 users and is greyed out in System 6. Its function is explained in BootBlocker Info above.
Bootblocker supports Balloon Help under System 7.


I have tested this software on a whole range of machines including G3 and G4 and Systems 6.04 to 9.2.1 with no problems, if you find a bug let me know and I'll try and fix it. (No promises).

Legal Stuff

BootBlocker is Copyright Paul D. Hart. You may distribute it freely but you must include this document. You may not modify the Software or this document in any way.
BootBlocker is supplied as is, the author will not be liable for any incidental, consequential, indirect or similar damages due to loss of data or any other reason. BootBlocker may be uploaded on to servers and BBS's so long as no charge is made for downloads. BootBlocker may not be distributed in any commercial way without the permission of the author.
Small parts of the source are (c) 1991-1994, David B. Lamkins and are used with his kind permission, many thanks to him for publishing his source code for Pwrswitcher.
Copies of BootBlocker at ftp://ftp.mrc-lmb.cam.ac.uk/pub/pdh/

BootBlocker is FREE - Enjoy. Paul D Hart.
email Internet :pdh@mrc-lmb.cam.ac.uk

Other Software written by me.
Shift SwitcherShift Switcher is a simple utility to disable the Shift Key of your Mac during the Startup process.
Copies at ftp://ftp.mrc-lmb.cam.ac.uk/pub/pdh/