[Trisquel-users] Re : Lost password on Trisquel machine!

[lcerf]

No, they are not.  They the GRUB user (certainly "grub") and password... that  
you have certainly never known.  Up to version 7, Trisquel had that password,  
which created far more problems (additional difficulty to recover a broken  
system) than it solved (basically none unless we are talking about a kiosk  
computer).  Trisquel 8 finally abandoned that GRUB password.  However, it  
must be still present on Trisquel 8 systems that were updated from Trisquel 7  
(and whose /etc/default/grub has never been modified to get rid of the  
password).

Anyway, as chaosmonk directly replied, mounting the filesystem containing the  
desired files from a Live system is certainly the easiest solution.  That is,  
assuming the partition is not encrypted (in which case, there would be no  
solution but to remember/brute-force the password: encryption works!).