you might have to do a few things. First off release and renew your IPs
Do this by in a CMD prompt by:
ipconfig /release [enter]
ipconfig /renew [enter]
Then clean out your ARP cashe, do this one of two ways
in CMD prompt by: (also you can do one entry by using arp -a to see all entrys, and arp -d 192.xxx.xxx [enter] (or whatever the listing is you want to delete)
Step 1 – Select the “Start” menu button and enter “command” in the search text field followed by pressing the “enter” key.
Step 2 – Input the following command at the MS DOS command prompt, “netsh interface ip delete arpcache” and press the “enter” key.
Step 3 – Wait for between 1 – 20 minutes for the ARP cache table to be deleted based on the version of OS installed on the computer. Windows Server 2003/2008 will normally take greater than 10 minutes to complete the task due to storing larger cache tables. Windows 2007 will normally complete the task in under 1-2 minutes.
If you get a error or it will not work do this:
Clear ARP Cache from Windows Control Panel
In the event you are not able to clear ARP cache from the DOS prompt or just are not comfortable conducting command line tasks, it is possible to clear ARP cache on the Windows OS from Windows Control Panel.
Step 1 – Select the “Start” menu button followed by choosing the “Control Panel” icon.
Step 2 – Depending on the version of Windows OS on the computer and the “view type” selected for Windows Control Panel, you may or may not need to choose the “Performance and Maintenance” menu option.
Step 3 – Choose the “Administrative Tools” menu option followed by the “Computer Management” menu choice.
Step 4 – Select the “Services and Applications” menu button located on the right-hand side of the screen.
Step 5 – Scroll down the menu options until you locate the “Routing and Remote Services” menu option.
Step 6 – Choose the “Routing and Remote Services” menu tab and a dialogue window will then open.
Step 7 – Select the drop-down menu and choose the “Disabled” option followed by clicking the “Ok” menu button to save the settings and clear the ARP cache.
Step 8 – Restart your computer and enabled the “Routing and Remote Services” menu option selected in step 7 to complete clearing the ARP cache.
After this, power cycle your dial up. Meaning disconnect and unplug all items. If your direct you will have to do a uninstall/ reset of your modem hardware.
There is a guide here from ehow.com on how to do that.
Just make sure if you needed any software/ hardware to get your connection working have it before you start. Usually with dialup windows will auto see it and run with it, just know your connection info and anything else you might need to dial up.
For info on netstat look here.
Info on ARP look here.