Open Network Connections by clicking the Start button , and then clicking Control Panel. In the search box, typeadapter, and then, under Network and Sharing Center, click View network connections.
Right-click the connection that you want to change, and then click Properties. If you’re prompted for an administrator password or confirmation, type the password or provide confirmation.
Click the Networking tab. Under This connection uses the following items, click either Internet Protocol Version 4 (TCP/IPv4) or Internet Protocol Version 6 (TCP/IPv6), and then click Properties.
The Network Connection Properties dialog box
To specify IPv4 IP address settings, do one of the following:
To get IP settings automatically using DHCP, click Obtain an IP address automatically, and then click OK.
Windows XP
Click Start > Control Panel.
On the Control Panel window, double-click Network Connections. QUICK TIP: Check the upper left corner of the Control Panel screen. Click Switch to Classic View to easily locate the Network Connections icon.
Right-click Local Area Connection then click Properties. NOTE: For wireless computers, select Wireless Network Connection instead then click Properties.
On the Local Area Connection Properties window, click Internet Protocol (TCP/IP). Then click Properties.
Make sure that the Obtain an IP address automatically and Obtain DNS server address automatically radio buttons are selected.
Click OK to save the changes.
Mac OS
Click the Appleicon then select System Preferences.
On the System Preferences window, click Network.
On the Network window, look for the Show field and make sure that Built-in Ethernet is selected. NOTE: For wireless computers, select Airport instead. For higher versions, select Ethernet on the left panel.
Under the TCP/IP tab, look for Configure IPv4 and make sure Using DHCP is selected. NOTE: In this example, 192.168.1.100 is used as the IP address that the Mac is automatically getting from the DHCP server.
, and then clicking Control Panel. In the search box, typeadapter, and then, under Network and Sharing Center, click View network connections.
If you’re prompted for an administrator password or confirmation, type the password or provide confirmation.
NOTE: For wireless computers, select Wireless Network Connection instead then click Properties.
icon then select System Preferences. 
NOTE: For wireless computers, select Airport instead. For higher versions, select Ethernet on the left panel. 
if you made any changes.