How to tell if installed?

If you have the preloader installed, does it always go to the first general page (shows preloader version)? I purchased a used Wii that I just power tested (booted up and asked to config remote) and then I resold it. A couple days later I was told that the Wii was hacked and it doesn't work. Now when it boots up, it goes the first preloader screen and I can't sync a remote. I'm trying to figure out if preloader was already installed or if the new person installed it. How could I determine this?

Thanks.

Basic logic dictates this:

If the Wii was not showing any signs of having preloader installed before you sold it, but it is after it was returned to you, then whoever bought it from you must have installed preloader.

Well I only turned the system on once just to power test the system. The configure remote screen came up and I turned the system off. So I didn't know if that could show if preloader was installed.

If it didn't show Preloader then, and this problem did not happen, they installed Preloader. Either that, or they configured Preloader to start. In any case, it is their fault.