The modem that came in my PCG-GRV670 Sony laptop is data fax only. I need to modify or add something to change that to use ez voice software ref www.internetsoftsolution.com/pages/download.htm. I am not sure what has to be done. Below is my configuration for both laptop and present modem.
OS Name Microsoft Windows XP Home Edition
Version 5.1.2600 Service Pack 2 Build 2600
OS Manufacturer Microsoft Corporation
System Name VALUED-51C59791
System Manufacturer Sony Corporation
System Model PCG-GRV670(UC)
System Type X86-based PC
Processor x86 Family 15 Model 2 Stepping 7 GenuineIntel ~2585
Mhz
BIOS Version/Date Phoenix Technologies LTD R0216B1, 12/3/2002
SMBIOS Version 2.31
Windows Directory C:\WINDOWS
System Directory C:\WINDOWS\system32
Boot Device \Device\HarddiskVolume1
Locale United States
Hardware Abstraction Layer Version = "5.1.2600.2180
(xpsp_sp2_rtm.040803-2158)"
User Name VALUED-51C59791\JJ
Time Zone Pacific Daylight Time
Total Physical Memory 512.00 MB
Available Physical Memory 147.38 MB
Total Virtual Memory 2.00 GB
Available Virtual Memory 1.96 GB
Page File Space 1.22 GB
Page File C:\pagefile.sys

Name CXT AC-Link Modem for Intel
Description CXT AC-Link Modem for Intel
Device ID
PCI\VEN_8086&DEV_2486&SUBSYS_813C104D&REV_02\3&61A AA01&0&FE
Device Type Internal Modem
Attached To COM3
Answer Mode Not Available
PNP Device ID PCI\VEN_8086&DEV_2486&SUBSYS_813C104D&REV_02\3&61A AA01&0&FE
Provider Name CXT
Modem INF Path oem12.inf
Modem INF Section Modem03
Blind Off X4
Blind On X3
Compression Off +DS=0;
Compression On +DS=3;
Error Control Forced +ES=3,2,4;
Error Control Off +ES=1,0,1;
Error Control On +ES=3,0,2;
Flow Control Hard +IFC=2,2;
Flow Control Off +IFC=0,0;
Flow Control Soft +IFC=1,1;
DCB 
Default <
Inactivity Timeout Not Available
Modulation Bell Not Available
Modulation CCITT Not Available
Prefix AT
Pulse P
Reset ATZ<cr>
Responses Key Name CXT AC-Link Modem for Intel::CXT::CXT
Speaker Mode Dial M1
Speaker Mode Off M0
Speaker Mode On M2
Speaker Mode Setup M3
Speaker Volume High L3
Speaker Volume Low L0
Speaker Volume Med L2
String Format Not Available
Terminator <cr>
Tone T
I/O Port 0x00002400-0x000024FF
I/O Port 0x00002000-0x0000207F
IRQ Channel IRQ 9

JJ in Nevada

The top line under the Requirements (http://www.internetsoftsolution.com/pages/download.htm) section is;
Voice enabled modem

You have quote; "data fax only"
(It appears to be Conexant based.)

ie; You can lead the horse to the trough all you'd like, but you can't make it drink if it has no mouth. (Voice = Mouth....) Err.. Onward.

You don't possess the hardware capabilities to utilize this service with what you currently have. You need a VOICE capable modem. (VOICE/FAX/DATA is pretty much bundled together with modems these days.)