How do I make a decent recording from a bad mic?

Most bad mics are that way due to not recording some of the higher pitches. You cannot make it do that, so you would have to only sing or talk in the lower pitches the mic can record, and THAT is a trick!
If you can get an oscilliscope, it can show you the range the mic can record it, and you’ll be able to see when you are hitting pitches you cannot record.

A very wise man told me that if you want a good sound you need to invest in a good mic.

If you still insist on using your built in mic, download Audacity (it’s free), use it to record your song, and use it’s built in noise reduction and sound compression features to tweak your recording.

@Blondesjon beat me to it. Both for the investing in a good mic & for using Audacity. So for what it’s worth, I second those ideas.

I’d like to add that if you do go the investing route, then maybe consider a Shure microphone. They’re good, and they’re durable.

Here are 5 great mics under $200.

It’s easy- remember these two audio engineering axioms:

1.) Garbage in = Garbage out

and

2.) No one enjoys polishing a turd!

That mic is designed for recording speech (and probably not for the sake of recording music like singing and instruments). The limitations of that mic are going to be its dynamic range (its ability to record soft and loud), its frequency response (its ability to record and reproduce tones acurately), and its inherent noise (the hiss and general lo-fi-ness!) So if you can live with that, then just be aware that those are limitations you’ll need to plan for.

On the mic side if you go into your control panel settings for sound, somewhere there may be a dial or slider for adjusting the mic input. If you set that slider lower you won’t amplify the incoming signal as much, which may reduce the distortion you’re hearing when your performance gets loud.

Proximity to the mic can also help to reduce distortion, but this comes at the risk of not picking up the low (soft) points of your performance. You could try and practice moving closer or further from the mic during the performance, a few inches may make the difference…if you’ve ever seen performers holding mics to their face and when they belt out a loud note they pull the mic away from their mouth a bit, you can see what I mean.

Lastly, try and mitigate any room reflections, to clarify the sound of your performance. With a Lo-fi mic, any unwanted room reverberation will just add to the muddiness of the sound.

Good luck with that…also try researching some USB mics…a company called BLUE (Baltic Latvian Universal Electronics) makes some great sounding USB mics for not that much money.

Cheers!

I find the below info about recording music from the net, hope this helps:
The first most basic thing in recording music is to connect your instruments or laptop microphones to the computer. On most computers there will be plugs in the back to choose from. One of them should be taken up by your speakers already. Near it should be a line in input. This is the plug we’re interested in. If you plugging a mic in, you need to either get a Quarter inch to 1/8 inch converter, or get a lead that has an mxl connection at one end and a 1/8 inch jack the other. Later on when you want to get better quality and things you’ll want to invest in a mixing board to connect to your computer, then connect everything through the mixer. Using an audio mixer will give you a lot more options in terms of what’s going into the computer. But for now just a mic to the computer will do.
There are probably hundreds of programs you can use to record music with, so first we’ll go over what’s important in a program. In a good music recording program you should be able to multitrack. Multitracking means you can record on separate track and the tracks layer over each other. So you can put down a guitar track, then vocals over the top, the more tracks you can do this with the better. Eventually you’ll want to add more instruments and use more tracks. The next thing the program should have is a bar that will tell you how loud the recording is and whether or not its clipping. Clipping is a nasty sound that the recording will make if your source is too loud. It sound like the music is distorting in a bad way. Another thing the program should have is cutting tools, moving tools, 1st and secondary record buttons and some effects are nice too, like reverb and delay.
Audacity
http://audacity.sourceforge.net/download/
Kristal
http://www.kreatives.org/kristal/index.php
Quartz Audio Master
http://www.digitalsoundplanet.com/SoftwareHouse/Products/Audio_Master/Freeware/freeware.phtml
Anvil Studio
http://www.anvilstudio.com/
Mixcraft 3
http://www.acoustica.com/mixcraft/download.htm
These are just a few suggestions, but as i said there are probably hundreds of different software programs you could use to record your music onto your computer. For the rest of the explanation of home recording we will use mostly Audacity.
Ok, so now you have your recording connected to the computer and you have a program installed. Its now time to get started. To actually record sound to your computer you have to make sure the write input on you program is selected. With audacity there is a scroll bar of different inputs. It’s on the right hand side towards the top. If you are going through the line in port then just select line in. If you’re going through on of the others just select them, not too hard to figure out. Now that your set up, hit record and test to make sure everything is working fine.
You should now be able to make recordings of your own music to share with others.

@ailsa Welcome to Fluther. Lurve.