Extend Windows File Length

Make sure that you have installed a functional microphone, and then start the Sound Recorder utility.
Click Record, and then let Sound Recorder run for 60 seconds.
After Sound Recorder stops recording, click Save As on the File menu, and name the file Blank.wav.
To increase the maximum recording time in Sound Recorder, click Insert File on the Edit menu, and then insert the Blank.wav file that you saved in step 3. When you do this, the maximum recording time is increased by 60 seconds. You can repeat this step once for each additional minute of recording time that you want to add. For example, for a 5-minute recording time, insert the Blank.wav file five times.
Save the extended Blank file.

Recording Voice File

As an alternative to an Ipod or Mp3 player, the backing track can be played in Windows Media Player whilst you record your voice on the Windows SoundRecorder. Wear your headphones so that the only sound recorded is your voice. Try to eliminate any undue background noises and, where possible, try not to sing into a blank wall, sing into an area where your curtains face you.
Unlike conventional recording studios, you will have all the time in the world to complete your recording and all this in the comfort of your own home.

Voice Popping
One of the most common problems when recording is an occasional  popping sound made by the singer. If this occurs use a  pop filter. Designed around the idea that everyone's voice is different,  pop filters provide user adjustable control of pop and sibilance filtering when recording vocals.

An easy and cheap way to do this is to stretch an old pair of tights over a coat hanger. Sing through this and any popping sounds will disappear.