So, here is what I did:
- I had Ophcrack Live CD downloaded from here
- Then UNetbotin tool came in hand to make my USB flash drive bootable with Ophcrack. Actually there was no need to separatelly download .iso image as UNetboot can be used to load various system utilities including Ophcrack as well as it can load various Linux distos
- I booted my friend's laptop from this USB stick (had only to check the video mode)
- Ophcrack started automatically, so I stopped it (this is optional of course) to delete some users from the list to reduce password cracking time by Ophcrackinging :) only the admin user
- About 10 minutes it took to get a88nr24 admin password
You can read more about Rainbow Tables used in Ophcrack here and more sofisticated here...oh, what the hell! Just google it! :)
The methods like this one were no good for my task as it was not enough access rights.
