What is it?
Modem - carpserv.exe
What does it do?
carpserv.exe? - This is a utility for Zoltrix and Conexant modems to allow you to listen to the modem as its connecting to the internet. This is more of a debugging utility that isn't needed unless your dialup is acting weird and you need to listen for line noise.
You'll want to keep an eye on this google search for any known viruses. The normal location of this file is C:WINDOWSSystem32carpserv.exe