A lot of the time it is either the challenge of getting the machine running or the necessity because right now he may not have the money to buy a new pc....he just graduated college and is probably working his first job.
Get memtest86 and make a boot disk from the ISO file. Then remove all but one stick from the motherboard, boot to the dvd and run the test for at least 10 minutes or if you have the time one full pass as it takes a long time to complete. If you see any errors just stop there and replace the ram with the other stick and run the test again. If it comes clean, run the pc on that stick until you can find a replacement for the bad stick. Most ram manufactures have a lifetime warranty on their ram. So get a RMA number from the manufacture and have them send a new stick. Test it when they send it to you!http://www.majorgeeks.com/files/details/memtest86.html
Next go to the hard drive manufactures site and download the ISO file for making their diagnostic program to check the hard drive. It is also a bootable dvd when you are finished. This program will tell you if the hard drive is good or dieing. There are two modes, quick mode and long mode, use both if the short mode comes up clean.
Some times the PSU can cause this type of issue as well. If you can beg buy or borrow (beg and borrow are best) a psu to see if it is causing your issue.
One other thing, change the data cord/ribbon going to the hard drive, you may have a bad cord/data ribbon.Do one change at a time
to be sure what you did fixed the problem...or not.