We have verified the symptom. It occurs due to the specifications of the operating system.
When a network adaptor exists in the computer, the operating system makes the settings of the network connection and automatically obtains an IP address.
When user starts the computer that is connected to the powered ADSL modem, the operating system will search for a DHCP server to obtain an IP address automatically. When it does not receive any response from DHCP server, it automatically assigns the computer with a private IP address and starts to make the necessary settings. This process affects the startup time of memory-resident programs and delays the total startup time.