He says the computer says the system cannot be restored.
Have your friend log into safe mode (F8 as he boots up).
Go to "Run" and type in
msconfig
Go to the "Start Up" tab and disable all. Go to the "Services" tab and click the "Hide Microsoft Services" and then disable all.
Close msconfig and reboot the machine.
Download AVG from www.grisoft.com (Free edition) and install, update and run.
Download Ad-aware from www.lavasoftusa.com (Ad-aware Personal edition) and install, update and run.
Tell your friend not to click on ads saying he is infected but they will sell him a program to take care of it.
No clicky!