One of the handier commandline tools for Windows XP troubleshooting is to blindly type “netsh int ip reset all” into the Start -> Run prompt. Here’s what it does, to my understanding:

• netsh: this is a Windows utility that allows one to display or change network settings locally or remotely. The first part of this command simply tells Windows which utility you wish to use; the rest of the command consists of arguments to this utility.
• int: this argument specifies that you wish to use the “interface” context within the netsh utility. An example of another context that could have been specified instead of “int” would be “winsock.”
• ip: this argument specifies that you wish to use the “ip” context within the “interface” context of netsh. An example of another context that could have been specified here instead would be “ipv6.”
• reset: this argument is an instruction within the previously-specified context and subcontext means what it says, to reset to default. An example of another instruction that could have been specified here would be “show.”
• all: this is an argument to the “reset” instruction. This should tell the “reset” instruction to set all of the settings in the “interface ip” context to default, but also specifies the file into which you would like a log of the “reset” instruction’s actions.

By resetting the Internet Protocol interface, a great many otherwise-mysterious problems can be made to disappear without complaint. Now we have a little better idea of what you’ve been telling your computer to do. Any additional light shed on such murky backwaters of Windows lore is always good, of course.

*Anecdotal evidence recommends a reboot after running this, though none should be strictly necessary.