I have two pc's and a laptop at home. My laptop has Vista (Wi-Fi), PC1 XP (Lan) and PC2 Windows 7 (Lan). PC2 with Windows 7 is the only one with which I can't surf the Internet despite a successful LAN connection to the router. All browsers show that the page can't be loaded. How can I fix this problem?
Win 7 is "actually" completely uncritical in terms of network and Internet - so I would assume that the error can be found either in the LAN cable or in the network drivers.
Check in the device manager whether the network card is working correctly and if so, replace the LAN cable
There can be two reasons for this:
The firewall of the PC is set so that Internet connections are blocked.
The router is configured in such a way that it just does not let this one PC into the Internet.
I would start there first.
In addition, I think it is dangerous to go online with PCs that have an outdated Windows that Microsoft no longer provides with security updates - this affects all of your three PCs.
My compis currently have either Windows 10 or a current Linux installed. I run software that does not run under Win10 in a virtual XP or 7-machine under VirtualBox, for which I have blocked Internet access (under Linux I have had very good experiences with WINE).