I suppose the error is due to the ability of some soundcards to recognise that a device has been plugged in. This happens with cards which can use their connections alternatively as outputs (for a 5.1 setup) or inputs. As long as the result is unaffected you can consider it only an aesthetical error, or - if applicable - you could manually adjust the input level to mic input if it's recognised as a line input, but I think that the input level is already more or less correct.
Different soundcards have completely different preamp stages, so there's no general rule. For instance my WaveTerminal 192X has only balanced line level inputs, I can't plug in a microphone and expect it to work as it does on my M-Audio Fasttrack Pro. And since you're using a dynamic microphone (in no way a condenser mic could cost about 5$) that's normal since dynamic mics aren't preamplified on their own, so the input level, unless you scream or sing at an appropriately loud volume, is normally low.
There's however some difference in preamplifying something and boosting the level in postproduction or editing, and that difference mainly affects dynamic range of the sound.
At your level of practice and knowledge there are, in my personal opinion, a lot of things you should read and decide before committing any money to a better system/microphone.
Some time ago a magazine did a practical test, giving low quality mixing equipment to professionals and high quality gear to to hobbysts like me. The pros had much better results at mixing conventional stuff than the hobbysts. So, in your case, it would be probably best to know and understand the limits and abilities of your equipment before investing any money in something that may not give the better results you're expecting.
Gear is important, but it's not everything. For example, for the stuff I'm doing right now, a $4000 Neumann U87 would work much worse than the $2 piezo capsules I'm using as contact mics, but a quieter external preamp would work much better than the preamps of my FastTrack Pro since I'm recording nearly at the limit of silence, and I pick up a little too much unwanted hiss generated by preamps. Not that I would dislike owning an U87, anyway