I've experienced some problems with my modem, when i try to connect to the internet suddenly appears a message saying that i haven't got any modem. What can i do to solve this problem. My modem is:
Name CXT AC-Link Modem for ALi
Description CXT AC-Link Modem for ALi
Device ID PCI\VEN_10B9&DEV_5457&SUBSYS_8175104D&REV_00\3&61AAA01&0&18
Device Type Internal Modem
Attached To COM3
Answer Mode Not Available
PNP Device ID PCI\VEN_10B9&DEV_5457&SUBSYS_8175104D&REV_00\3&61AAA01&0&18
Provider Name CXT
Modem INF Path oem1.inf
Modem INF Section Modem02
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 ALi::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 L1
Speaker Volume Med L2
String Format Not Available
Terminator <cr>
Tone T
Memory Address 0xFBEFE000-0xFBEFEFFF
I/O Port 0x0000FA00-0x0000FAFF
IRQ Channel IRQ 10

Take with a grain of salt I'm not sure on internal modems but for external modems you need kppp installed
set it up and choose /dev/tty3 as the device and go from there (Your machine looks for it on COM Serial Port 3 see above)

http://linmodems.technion.ac.il/
Use scanmodem and read the instructions.
Install wvdial
it will be easier for debug than kppp

Hope this helps, I think you may have a winmodem