Without knowing the device in question, it's impossible to determine which is the best for trouble shooting and which is the worst. There are many tools desgined to help in my trouble shooting issues from industrial purposes to technological.
which troubleshooting model is the best and which one is the worst
S&W Model 14
There is no best and/or worst army in Warhammer 40k. The points system is mostly fair and reflects how these armies should be played. Tau are good at shooting but not so much at close combat, same with Orks and Tyranids, they're not the best at shooting but can eat you up at close combat (most Orks have a BS of 2 I think)
Best of Shooting Star was created in 2001.
the best website for shooting games are stickpage.com
3rd is the worst 2nd is the best and 1stis the one with the golden chest
T-Mac has the best shooting style.
Best of the Worst was created in 1991.
Prone
Worst and best are each other's antonyms.
Worst Best Friends was created in 2002.
The best option for a PC help with problems would be to find a trouble shooting guide for your particular PC. This would be a good way to start. PC support the website has many of them.