Can't reset admin password with usual methods

I have a MacBook Pro with a 2.16 GHz Intel Core Duo processor and 2GB 667 MHz DDR2 SDRAM which I bought used some years ago. To the best of my knowledge it doesn't have an admin password. On the very rare occasions when we've been asked for one I've just hit 'return' and been able to continue without one. Until now...
I would like to install rEFInd, create a disk partition and run Xubuntu on the other side of the partition. Terminal informs me that I need to enter my password in order to run sudu and install rEFInd.

I tried to reset the admin password by inserting the first install cd, holding down the C key, going under "Utilities" to "Reset Password" and...resetting. I chose the identity "System (root),' as that was the only option offered. I was then told that I didn't have permission to reset that password, or else there had been a failure.

I also tried following the directions under the first option here: http://www.macyourself.com/2009/08/03/how-to-reset-your-mac-os-x-password-without-an-installer-disc/ I set a new password (I think). I tried again to enter my password in Terminal. It didn't show the pw I enetered at all, and every time I entered it and hit Return it gave me an error message. Any ideas?

Is there any other way to reset--or create--my password? Or to get Terminal to allow me to bypass that step?
Any advice greatly appreciated. Thank you.

A warm welcome to Mac-Forums.

You haven't given much info about your Mac - which OS for example.

Here is a link to several different ways of resetting your Admin PW. Some of these will apply to most operating systems; one or two need a reasonably up-to-date OS.

http://www.macworld.co.uk/how-to/mac/what-do-if-youve-forgotten-your-mac-password-3594395/

Ian

Sorry about that. It's running OS X 10.6.8
I tried the Recovery mode fix to which you linked and wasn't able to make it work. The computer booted into what looked like its usual mode. I went into Disk Utility but didn't see a "Continue" button. I also tried going into Terminal under Utilities and typing in resetpassword I got the following message: -bash: resetpassword: command not found

That explains a lot. Snow Leopard, 10.6.8, has no Recovery Partition (that started with Lion) so you can't take that route. Whilst I openly acknowledge that Snow Leopard is a very robust and much loved OS, it is six versions behind the current macOS Sierra.

However, as you have the disks, try the method described in this link which deals with Snow Leopard: https://discussions.apple.com/docs/DOC-4931

Here is a method, again specific to Snow Leopard, but for those who have lost their disks: https://discussions.apple.com/docs/DOC-5381

Please post back.

Ian

Thank you very much! I tried the disk-free boot method twice, understood when i needed t press 'enter' the second time--and it worked! Thank you for the links, and thank you for your patience with my first unclear formulation of the question. Thanks again.

You are very welcome.

Visit us as often as you wish. We try to help.

Ian

It worked well - give Ian some credits by hitting the little thumbs up in his post.

Can I just add, please do a full backup before running rEFInd. Partitioning your HD is not a step to be taken lightly and the chance of loosing everything is a possibility and reversing the procedure should you wish to do so is a nerve wracking and dicey process (I've done it myself) level of difficulty 9/10.

The best insurance by far would be to use the free Carbon Copy Cloner Version 3.5.7 Available here https://bombich.com/download#unsupported to create a clone that could be used to recreate your present HD should everything go pie shaped. It must be the version for Snow Leopard.

Note this is an old and now unsupported version of CCC but we here at Mac Forums swear by Bombich software's CCC. Your only outlay will be the price of an external USB hard drive and the short time required to erase/format it to Mac Extended Journalled with disk Utility. (30secs)