Does the Internet Provider support the same Flex or V90 standard. 
If they are V90, and your modem is not a dual flex/V90 modem you
may need to run the upgrade flash to make your modem V90. (ISA only)

Make sure you internet provider settings are correct and that you are dialing 
into the right number?

Does your computer reach the minimum requirements of the modem?

Go into your Bios menu by rebooting, upon bootup when it asks you to press 
a specific key (usually DEL) to enter Setup or Bios press it.  Go to 
Chipset Features Setup and look on OnChip USB and USB  keyboard support. 
Make sure both of those are enabled. 
Go back to the main menu and go to the PCI/PNP Configuration menu.
Make sure that Reset configuration Data is set to enable. Save and Exit.

Go to the my Computer Icon, right click the mouse button. 
Select Properties.  Then click on performance.
Click on the Graphics button.
Set the Graphics acceleration to one notch above none.
Click OK and exit.

Go to the Modem Icon in control panel.
Click on properties.  Click on Connection.
Click on Advance
In the Extra Setting box enter the following.
ATS10=240S38=250

Verify that the modem’s IRQ is above 9.  To verify go to the My Computer icon.
Right click and select Properties.
Click on Device Manager.  Double click on the Computer option.  Make sure that 
The IRQ (Interrupt) circle has been checked.
Verify that the Modem and/or Modem Enumerator are both on an IRQ
above 9. 
If it is not, then please send an email to www.amquestmodem.com with the 
Subject title IRQ CHANGE.  A reply will be sent to you on how to do that.

If the modem disconnects after a period of about half an hour or more it can
Be due to sudden burst of line noise or the internet provider going through a
specific cycle.  Might want to try a different phone number from the provider.