But https://www.amazon.com/Asus-G20AJ-US009S-i7-4790-Windows-Desktop/dp/B00OFQR38C and other discussions tell me this machine isn't without issues. It's small form factor is a definite issue for owners that don't know to use canned air every few months and as time passes there can be other issues.

For me the tools Speccy and Userbenchmark have been very helpful in spotting the usual issues. But if the owner is not keeping up with maintenance, no app can help.