Sometimes, the networking layer in Windows gets corrupted. Of course you don’t necessarily know why…
There are a few easy steps to fix it. The best one, in my opinion is a good old driver update which will not only reset the stack but will also bring you more stability. Check with your computer manufacturer/chipset vendor for that.
Alternatively or if you already have the best available driver (big up for staying up to date, here), you can issue a command to reset the TCP/IP stack:
- In XP, from a command prompt, type the following: netsh int ip reset c:resetlog.txt
- In Vista/7, from a command prompt with elevated privileges: netsh int ip reset
(logging the results of the command is optional in Vista/7)
A reboot is recommended after as a few registry keys need to be regenerated.