This is as basic and as cheap as it gets. I am assuming that you own a Windows based computer of some kind and that's it's running on XP or Vista. You want to make a recording but only have either a built in mic, as do many laptops, or one of those discount store computer mics that cost $5-$10 dollars. You can still make a recording. Windows has recording software built in. Not great, but it will work.
It's located at Start, Programs, Accessories, Entertainment, Sound Recorder.
Here is a tutorial for Windows XP.
Here is a tutorial for Windows Vista.
Looking for more advance recording software but have a limited budget?
How about free? Click here for a list of free recording software.