I have it too. Only 1 account number in my case.
Searched Google, seems to be Windows Messenger settings:
quote:
Originally posted by http://www.newsarch.com/archive/newsgroup/microsoft/public/windowsxp/general/msg90217.html
HKEY_CURRENT_USER\S\P\2846389128
(where the final number may vary according to machine)
was recreated, (if I deleted it) each time I ran Windows Messenger version
4.7.3000
It is NOT created, when running the version of Windows Messenger prior to XP
Service Pack 2 (ie version 4.7.2009)
My advise would be leave it there. Harmless Windows Messenger settings, wierd Microsoft didn't put it in a regular key though.
EDIT: Confirmed, the number is your Messenger account ID.