Seek for HSP PCTel288IA modem? Try this.
Step1 Download and unzip.
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
Make a call. Done.
If fail, try to disable com2, and try again.