One of the signs of a hoax is that it always happens to a friend of a friend. There's rarely a direct line of attribution which can be followed. And a hoax doesn't necessarily mean that the person who sent the warning is trying to scam anyone, just that he is forwarding what he believes to be a valid warning.

While I don't doubt that your Master's friend's computer may have been infected, one of the warning flags of this one is that he had to "scrap his pc and brought another one to replace his old pc". At worst, a virus would infect the hard drive only, and the most drastic solution would be to wipe the drive and reinstall the OS. In most cases even that would not be necessary. A combination of anti-virus and anti-malware software should solve most virus issues. A trip to a local expert might be necessary some times. And at the very worst, replacing the hard drive is a much less expensive repair than replacing the whole PC.

But regardless, it's always a good idea to be careful of opening executable attachments in emails, especially if they are from someone you don't know. It's also a good idea to have a good anti-virus program running on your computer, and to keep it up to date. There's a lot of good information out there about how to protect yourself (and your computer) from malicious software. Everyone should make use of those resources.