When you dial a 9 to select an outside telephone line, you receive:

STOP 0x000000D1 (0x00000008, 0x00000002, 0x00000000, 0xBFE7EB74)
DRIVER_IRQL_NOT_LESS_OR_EQUAL
.

You may need an updated Ltmdmnt.sys driver for your LT Win Modem. Check the modem vendors web site.

If the modem vendor doesn't have an updated driver, install the generic LT Win Modem driver version 6.00.