Dial-up Modem Will Not Disengage

[Lana]

Sorry. I'm Lana and I'm new to community but haven't had time to introduce myself yet. I need help fixing a problem with my sister's computer. After setting up an infolink on her phone line, her computer more or less blew up. Apparently, by establishing the downlink while her computer was turned on and plugged into phone line, no connection to internet established at time because line is shared by phone and computer, analog modem interpreted line as digital and will not disengage. There were many other problems created--lost modem and audio files, inability to access XP, etc., etc.,--but at this point, all have been fixed and device manager shows + for all devices and indicates that all devices are working properly. I have tried unplugging all telephones, unplugging infolink, but modem will not disengage. Am in the process of doing a repair on Windows XP while everything is unplugged hoping this might disengage modem, thinking that if infolink and computer are not plugged into phone line at same time, problem will not reoccur. Please let me know if I'm on the right track, or if not, what else can be done. My sister has a high-end Dell; operating system is Windows XP, SP1; modem is BCM v.92 56k Voice Modem. Thanks!