I'm looking for a piece of equipment that can capture the caller ID and send it to a Windows-based computer. Does someone know of something like this, or a more appropriate forum?
In general a lot of existing solutions became unsupported a long time ago. Often they only worked on 32bit versions of windows as they rarely released an update to support 64bit versions.
But. US Robotics branded modems appear to still be supported.
I believe the USR5637 56K USB Faxmodem might work.
plugs into USB port, has firmware and software support on modern versions of windows 10.
For debugging you can open a terminal window to your modem and issue the commands required for it to start printing out caller ID info if you already have a modem and just want to see if it supports printing out the detected caller ID data:
AT+FCLASS=8 AT+PCW=0 AT+VCID=1
This software appears to do the job of recording the caller ID data and other enhancements :
Modern solutions targeted at business users generally use VOIP. Many VOIP systems and service providers now provide a mechanism for webhook type API call on call events and you take over from there. (Basically their server sends a web page request to your server with parameters of the call in the request)
example webhook API from a voip provider: