try disabling your firewall...
Lets try and see whether you have equipment related problems. In this step, we will allow the equipment to self-diagnose and resolve the problems. If you suddenly lose connectivity over your High Speed Internet line, have a slow connection or are unable to browse the Internet despite indications that you are connected, it is possible that your modem is not communicating properly with the Internet network. Save all your current work, close all open applications, then shut down your computer ...unplug router and modem
Power up the modem first and after it gets initialized and all the lites are steady..
power up the router...after all the lites are on...
power up the computer ...
The above steps should take care of your problem
then try this.. TCP/IP stack repair options for use with Windows XP with SP2.
For these commands click on Start
..... type in...CMD
....to open a command prompt box
Reset WINSOCK entries to installation defaults...type in ... netsh winsock reset catalog
.... press ...enter
Reset TCP/IP stack to installation defaults...type in...... netsh int ip reset reset.log
... press ...enter
Edited by happyrock, 24 December 2008 - 10:18 AM.