|Presuming it won't go into safe-mode... If it will then you have means of recovering personal files etc. first...|
If no safe-mode and (s)he has files (s)he'd like to save...get a Linux disk and boot up with that. Then you can access files and save them to external media (usually optical of course); and ideally verify the copies are accessible on another system too. Ubuntu is one of the favourite Linux variants; and can be downloaded as an iso and burned to dvd. Boot with that dvd and safe his/her files...?
Most laptops have a Recovery partition on them; and although most don't do it...the manufacturers advise you make your own recovery disk set too when you first boot up the system.
You may find the standard Recovery routine will do what you want; but it WILL wipe files in the process - which is why I suggest the Linux boot disk approach to save files first...
What make/model laptop is it you're working on?
message edited by trvlr