Any web browser can open a file on your local storage just as easily as one from a web server provided it recognises the file format.

Must be to do with the MS set up system using trusted proprietary software so no permissions required

an old XP will not have the necessary code to open most https web pages – you can check as this forum uses the old standards and is accessible by old browsers but some of the image hosting sites use a higher level of security (actually a larger number of bits to hold the ‘key’ to the crypto) and these photos won’t display

the XP’s default setup to open almost anything offered to it made it too easy to exploit – it was possible by turning off the various options to be considerably more secure but lacking the necessary higher level crypto cannot open most modern pages so now best used to run unconnected to the web.

Unlikely – the router and network don't trust Microsoft, or anyone else.

More likely bing has cached some pages locally, and isn't using the network. It fails when a page can't be found locally, and the computer has to get it from the web.

As Michael says 'it cannot see any other device on my wi-fi network, and it cannot access the internet' I suspect the XP network configuration is wrong. Assuming a physical cable to the router, in network settings:

First thing to check is the XP sub-net mask, which controls how IP addresses are interpreted. Home networks are usually 255.255.255.0 All devices on the sub-network have to share the same mask; if not their IP addresses are incompatible.

Second thing is that XP has a valid IP address. Could be static, where an administrator allocated and set the address in both computer and router. More likely, XP should be set to ask the router for a dynamic address at boot time (DHCP).

XP can't connect to the network without a valid IP address.

After that we're into driver and hardware problems. Wifi works the same way, with an additional layer of complexity – it's encrypted, requiring passwords, and protocol and other settings. Fault finding, always get it working with a cable first.

Dave