Transfer telephone recordings to computer hard drive??

I have messages on my digital telephone answering machine and would like to transfer those onto my computer (XP-Media Center Edition).
Is this possible?
Can I just purchase an adaptor and/or plug thingy or do I have to purchase an entirely different recording device and transfer the recordings from my answering machine to the device to my computer?
Do I need to purchase special software too?
Anyone know if and how this can be done? (I'm not to computer savvy or literate.)

I can plug a headset into the phones/answering machine

You could use windows sound recorder to record them into a .wav format. Also there is a free sound recording program at http://audacity.sourceforge.net/ that is called Audacity that as long as you have a microphone imput to your computer for your digital phone you can record them as .mp3, .wav and a few other formats using Audacity.

Does your answering machine have any kind of an audio output jack? If not, then you'll just have to stick a microphone next to the speaker.

if you can plug in headset,
suggest plugging into tape deck and record,
and/or plug in to auxiliary input or mic input,
on computer and record from there,
check sound/volume settings in control panel
on computer for input,

If you have a dial up modem, which most people usually do as a standby, then you can hook up your RJ11 or RJ 45 cable to the comp and enable the use the comp as a phone facility.

Once you've done this, you can save all the audio files in the format of your choice in a separate folder.

However, I'd suggest you get the local technician to come over and set it up for you and teach you, on site, how to use this.