Weird problem - some webpages wrong on multiple browsers, this machine only

I have several machines, and only my main one does this. With every browser.

On the Gumtree webpage, search finds nothing. Also the Universe@Home forum displays the banner odd - it moves up as you scroll, obscuring part of the page. I've not noticed any other pages incorrect yet.

Can anyone think of something which could interfere with all browsers like this? I have a VPN but it's off. It's not even sat in the background. I use Oracle Virtualbox which makes some odd connection in the network connections list, but I closed it and disabled it in network connections. I have a bridge to the other computers from this one (which is directly connected to the internet router), but I tried removing that.

You can play with control panel -> internet options
Some of these options are deprecated with internet explorer but there are some which are still in force such as TLS.

A quick test you can make is to reset internet options, "advanced" and "security" tabs have reset buttons.

Well I decided to fiddle with the bridge. I recreated it and made things worse. The bridge got no IP from the router through DHCP, I had to put it on manual. The problem persists, but it's only a floating banner which shouldn't be floating on one webpage, and I just blocked it with adblock, should have tried that in the first place. The Gumtree searches I can do on another machine. However there are probably other pages which aren't working right because of this. I guess I just try the other machine, like I'd normally try another browser if I suspected that.

How on earth could windows possibly manage to edit a webpage as it's being given to the browser?! Actually reinstalling Firefox made it work ok for 1 day then it broke again. This is very weird!

I think I've had enough of fiddling incase I break something else!

P.S I've already deleted the repository folder and let it recreate it.

zebal said:

You can play with control panel -> internet options
Some of these options are deprecated with internet explorer but there are some which are still in force such as TLS.

A quick test you can make is to reset internet options, "advanced" and "security" tabs have reset buttons.

Click to expand...

Done, although one was called "restore advanced settings", which I assume must be the same thing, it's terrible English. It sounds more like it's going to restore them from a backup I've made.

It hasn't fixed it though. How can Windows be very slightly breaking webpages in all browsers? This makes no sense at all. Is there a way I can trace between me and a website to see any interceptions with any software on my machine?

Lamberto Vitali said:

Is there a way I can trace between me and a website to see any interceptions with any software on my machine?

Click to expand...

You can check if there is no proxy set in windows settings -> network & internet.

You can also try boot into safe mode with networking and see if problem persists there, this would tell a lot.

You could try an in-place reset. I generally suggest this as it doesn’t loose files and apps, but refreshes the operating system, possibly fixing the issue.

I shall try Zebal's suggestions first. There is no proxy set in internet settings. I booted into safe mode with networking, but I have no internet access. I should point out I have a network bridge in Windows. This machine has two ethernet adapters - one wired to the ISP's router, and one wired to a mini unmanaged switch in the garage, which has 7 other PCs connected to it running science programs. This is so I can monitor internet traffic from here. Now because of this weird web page problem, I suspected the bridge, so I deleted it and recreated it. Ever since then it's not working in auto mode. DHCP fails for this machine. It claims "no internet". While not in safe mode, I can change this to a manual IP and input the auto one I had from before and all is well, but in safe mode it doesn't like it. I also can't seem to find the page where I can see the bridge as an icon to disable or delete it to stop it messing things about.

Lamberto Vitali said:

but in safe mode it doesn't like it.

Click to expand...

likely because bridge adapter is not enabled in safe mode.

Lamberto Vitali said:

I also can't seem to find the page where I can see the bridge as an icon to disable or delete it to stop it messing things about.

Click to expand...

You should be able to find it in control panel -> (view small icons) -> network and sharing center -> change adapter settings

I'm not sure bridge can work in auto mode if there is no DHCP server or (check DHCP service is running),
in "change adapter settings" right click bridge adapter -> properties -> double click Internet protocol v 4 (IPv4...) and set IP manually.

if there is no bridge adapter in "change adapter settings" create it. (by selecting 2 other adapters and right click...)
this should help in testing things in safe mode.

I really don't know why would bridge adapter be a problem for surfing but it sounds like a possibility in your case.