This seems to be a definite reformat. Even at my rate, the time spent to repair this machine would cost as much as new Dell.
If he doesn't have install disks, he almost certainly "borrowed" all his "costly" software.
I'd even be uncertain about saving the data, as it may contain the infection.
Copy the data, reformat and reinstall and let him know the data may be infected. A good scan should be run before installing the data.
I've had to give up on a few machines due to time/cost restraints, and it may be the best answer in many cases.