Here's the trouble: my guitar recordin doesn't sound as I hear my guitar. Seems to hear kind of iron straws of wobly strings. Is it because of an indirect/flawed micro recordin (realtek), or is it my own perception altered somehow?
Might be worth checking that there are no effects on the track that's playing back and/or that Windows (or your soundcard driver) is not "enhancing" (= distorting) all playback.
Right click the speaker icon bottom right of your computer screen, select Playback devices, Speakers, Properties, Enhancements, see image below, and ensure nothing is checked in the list (4) of available effects - you will have to scroll down the list to see them all.
If an electric quitar then you would be better feeding this into a USB audio interface that can handle guitar input.
If acoustic guitar, then you really need a mic designed for this. If using a general mic the placement is very important as if it is off axis, colouration of the sound can occur, again a good mic fed through an audio interface would be best.
In both cases I have suggested using an external audio interface, the reason being most of them have a headphone output so you can listen to the instrument directly while recording, good makes are M-Audio, PreSonus, FocusRite, Roland, Behringer etc.
The audio interface provides a several advantages:
better sound quality conversion than using the sound card.
you can hear the sound as the mic is picking it up, most units have an output for headphones, not direct with your ears, if that is what you meant by 'is it my own perception altered somehow'.
This is important because the room acoustics that you hear are not the same as the mic picks up.
you can test and adjust the sound set up, ie mic positioning and levels, without recording.
the ability to also input a second (or third) audio source, eg vocals, at the same time as playing if required.
Whether you need / use one depends on how far you want to take the recordings.