if the board was the only thing bad i'd suspect the psu's 5vsb rail or caps on the mobo.
i just switched from an nforce 2 chipset board to another nforce2 board, had to reintsall smbus drivers and maybe sound. usb drivers/devices were uninstalled and reinstalled
my old psu destroyed the motherboard because the standby power(5vsb) was not well regulated (sometimes) during plug in(it can go back to normal and disguise the problem). symptoms are a hot southbridge and no post, by that time the board is already damaged so check the psu. I think it damaged my keyboard since some sources say that usb and nic (lan) is powered by 5vsb so that it can wake the computers from standby either via keyboard or lan boot. I had some problems getting the pc to boot before it totally failed. it would work normal when it posted. Other than that, none of the components failed since they were not powered during the psu "failure" (cpu, ram, hdd, dvd-rom).
This happened in the summer when I was moving the computer to a cooler location and then back up to my room. the many plug ins must have sent short duration unregulated power(faulty psu) to the board one too many times.
if it's sata make sure the compatible drivers are installed (i'm not sure how)
edit: ok i googled ASUS A8M2N-LA and i see that hp sells it (oem only board I suppose). i'm guessing this is an hp machine and since hp is cheap on parts I'd DEFINITELY suspect the psu as the cause(what you are suppose to do to test faulty 5vsb is either check the caps on the 5vsb in the psu or get a multi meter and try to read the output watching it fluctuate during a plug in/psu switch on (away from any motherboards). it might vary from too high(12v) to normal in that instant which is what can mask the problem.
edit2: so the third google result showed that hp uses that mobo in the hp model m7580n computer, i G'ed it again and i get this
http://www.tomsguide.com/us/hp-m7580n,review-810.html
it has a bestec psu, a 300 watt one, the 250watt ones bestec 250-12e were known for taking out motherboards when they "died" because there was no overvoltage protection on the 5vsb. I didn't even know about this, since I had one, I have my friend's broken one on me as well. if you google for the bestec model 250-12e failure, you might come across a review that stresses a "dead" bestec to see what the problem is. that's how i know the minute 5vsb instability might be the cause of your friend's woes. it seems that other than the bad caps on the 5vsb along with no overvoltage circuitry on 5vsb, the psu is quite decent(it took a giant beating in the review and survived) in supplying it's power, at least it won't get overloaded too easily at spec.
I have a question for you though, how old is the system and does your friend do heavy tasks? (i'm what you consider heavy(+maintenance) and mines lasted 6 years so i think I got lucky)
psu's have caps rated for certain temperatures and since electrolytic caps can dry out, a low resource user might postpone such a failure if only by a few years by not heat stressing the system or unplugging it.
this is all really assuming that it's an hp machine(gateway, acer, emachines are suspects in cheap parts dell, sony, apple who knows). also it depends on what version of windows is installed, if it's oem then it won't be a valid licence anymore on a different motherboard.
try getting the same chipset northbridge and southbridge and if it's retail windows then it will likely just work with minor dirver issues. getting compatible sata drivers will allow you to boot.
