The MSN messenger 5 is a completely different messenger from the one you had previously, which was I assume Windows Messenger 4.7. That should still be on your system, but they both cant run at the same time on the same account. After installing the MSN messenger v5 on several systems, and learning that it was not an update to the one I already had, I un-installed it. The 4.7 was still there. See if you can stop MSN message and start the windows messenger and log in, then see if the phone thing works again. I saw on winXPnews that the two were different, and the new one is not what an enterprise would use.