Certificate error win xp?

Got win xp on an old laptop and a few updates were installed automatically and still can't surf the internet. The time and date are correct and when I go to the Internet it says on some pages: This website can't be displayed even though I have Internet. On other pages, however, it says: There's a problem with the website's security certificate. I think it could be because updates have to be installed, but you have to look for updates on the Windows page, so quick search is there: The desired page can't be displayed because a problem has occurred on the website.

Then your XP computer does not trust some CAs. E.g. Letsencrypt or one was changed and XP can't or does not know the cross-signing

There have been no updates for Windows XP for years. There are also none for browsers used on this system. Therefore the system does not support the currently used encryption algorithms that most websites are now using. That's why you can't surf with it.

Then the CA (Certification Authority) or the appropriate decryption is missing.

Apart from that, you should keep your hands off XP by now and don't use it on the Internet. Worms get in faster than you can see.

Better to pack something like Linux (LUBUNTU, for example) on your system.

With the last firefox version for xp you can still surf the net, as firefox carries out queries on certificate servers.

XP used to be great, but is no longer possible!