How to force bios to boot from usb

0

Imagine you have Hiren's Boot Rescue CD on a flashdrive on a flashdrive, and your intention is to restore windows password, but you cannot access the bios, because it is locked with a password. I searched on the internet and did not find anything, just tutorials on how to boot from usb with modifying bios, but they were useless in my case. Is there any way to boot from usb WITHOUT:

  • Modifying bios manually
  • Accessing any OS installed on the system

Note: I will NOT use this for destructive purposes, I'm just interested in what to do in this case.

Regards

Yogibear

Posted 2016-03-20T11:35:31.203

Reputation: 3

Reset the bios? – DavidPostill – 2016-03-20T11:40:30.487

To be clear, I'm interested in can I somehow evade bios password using an USB that has a live OS on it, I need to force the system to boot it. If this is not possible with an exploit or something like this (maybe a firmware), do I need to reset bios using generic password? Are generic passwords reliable? Again, I need this for non-destructive purposes. Thanks in advice – Yogibear – 2016-03-20T11:43:20.590

Resetting the bios depends on what hardware/bios you have ... there may be a jumper or you can remove the cmos battery. There is also BIOS Password Backdoors in Laptops. As it stands your question is too broad to answer.

– DavidPostill – 2016-03-20T11:47:18.240

Are backdoor passwords working on PC-s as well? – Yogibear – 2016-03-20T11:47:58.833

I don't think it would be too broad, as I mentioned, I'm asking for things like firmware overwriting, something similar to exploit BadUSB. But if this is TOTALLY not possible, let me know. Thanks – Yogibear – 2016-03-20T11:50:31.393

No idea. I've never had to do it. See also How To Remove, Clear, Reveal, Unlock or Reset BIOS Security Password

– DavidPostill – 2016-03-20T11:52:07.313

I checked the site out you included in your comment, It mentioned that I could run FreeDOS on an USB, but I'm not sure, this drives back to the original issue, to run live OS from an USB, I think maybe only the Bios manufacturer generic passwords would work, but I don't think they are that reliable. Maybe someone can answer the question. I think we would need to overwrite the default firmware of the flashdrive with a code that could exploit the bios. I'm not sure. By the way, thanks for your efforts on trying to answer my question – Yogibear – 2016-03-20T12:02:29.563

Remove The HDD and than boot the system at that time in boot order your BIOS will not find HDD so that it automatically boot from the USB which boot order is after the HDD. – Akshay Pethani – 2016-03-20T18:50:22.213

Answers

2

This really depends on the BIOS settings - in some cases you can't do it without modifying the BIOS.

I would not recommend it, but it should be possible to open the system and remove all bootable disks, then see if the BIOS will boot from USB. If the BIOS is set to read hard drives first, then anything else - not an uncommon setting - it will work. The difficulty you may have is plugging the hard drives in afterwards. Theoretically this can work as SATA supports hotplugging of disks (and yes, I do it routinely - on known hardware). It is, of-course, possible you will land up frying your MOBO or hard drive.

If I were trying to reset a computer password without BIOS access, I'd be inclined to remove the hard drive and put it in another PC, then perform the appropriate reset operations.

davidgo

Posted 2016-03-20T11:35:31.203

Reputation: 49 152

Thank you, but I'm not sure wheter BadUSB exploit can be used to run a cracker while booting, because the pc recognises the flashdrive as a HID and executes the scripts. I'll try, and see if I can accomplish it with this kind of approach. – Yogibear – 2016-03-20T19:00:29.537

I did some research and I don't think BadUSB would be suitable in this cases, because what do you do with a "keyboard" script while booting... Maybe If it tries to bruteforce the password. Maybe the easiest would be if this happens to use the passwords provided by the manufacturer (I'm not sure are they working on PC-s), or physical access is needed. One more question, are those generic passwords reliable, and can be used on desktop computers instead of laptops? If you can answer this, I'm thinking of marking this as the answer, and thanks for the efforts you made to answer this question. – Yogibear – 2016-03-21T16:16:53.633

Okay, I'll mark this as the question, because it is helpful, though it is not exactly what I was thinking of, it is helpful for the others. – Yogibear – 2016-03-27T08:16:54.327

Asked: 2016-03-20T11:35:31.203

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Active: 2016-03-20T18:23:53.997