I've posted this problem on numerous forums, but to date, no one has been able to help. I have two computers connected to a LinkSys router. The Win7 never has any problems. The XPSP3 at least once a day, and sometimes more often, loses connectivity. Sometimes powering down the router helps; sometimes not. Sometimes I have to reboot the XP machine. And before I lose connectivity, http requests get wacky. Sometimes, I get URL not found or Invalid URL /....then a short while later, it's OK. I can always ping sites, but when the problem really hits, all HTTP requests fails and I also lose mappings (both computers are connected to a network file server). However, I can still ping. BUT the Win7 never has problems.
I've spoken with LinkSys ad nauseum but they have no solution. When the problem occurs, Network Magic shows nothing wrong. Also, the XP computer frequently reports it is disconnected from the internet, then, immediately reconnects.