Looking for PCTel288IA modem driver, try this.
Step1 Download and unzip the file.
Step2 Add New Hardware - select Port
Step3 Click Have Disk - select PCTel HSP communication port
Step4 Reboot system
Step5 Add modem HSP 336 Deluxe
Check Modem - Diagnosis - more info
Plug in phone line. Dial a call. Done.
If fail, try disable com2, try again.