Follow the given steps to record your voice in windows XP:

To use this feature, you will need to be logged into your computer with administrative rights.

To start recording process, first make sure you have attached a microphone
to your computer.


First click on Start button> All programs> Accessories> click Entertainment and then click on Sound Recorder option


Now a small "Sound - Sound Recorder" will appear, go to File menu and click on New to start a new file for recording.
Click on Record button to start recording process and start talking then click on Stop button to stop the recording.

Now again click on File menu to save this file with .wav extension to a folder of your choice
Now send this voice file as an attachment via e-mail message to your friends.