I have been trying to connect to my local Hospitals Personal Health Records, which closed for maintenance beginning of June for 3 days, but I cannot get a CONNECTION since. I have a PC and on both I get the 404 message. Have cleared caches but to no avail. However, on my next door neighbours PC, connection is there. On my PC, W10 and Microsoft EDGE. On my Apple Tablet on Safari and Edge. Same result on each one. All other WWW addresses obtainable, just the one. Any ideas please in SIMPLE English?check your security software, like your AV program, browser adblocker or add-ons in general, modified HOSTS FILE etc.in other words, things that you would have that your neighbour wouldn't.things like adblockers can be disabled, AV software can can temporarily turned off.
other avenues; try a different browser on your PC, reboot your modem.
Thanks for your reply. I have managed to get round the problem but cannot understand why . Every time I try to get the site by typing in the www...into the address bar it  returns the 404. However, when I put the details of the site into the SEARCH box, it comes up with the SAME www.address and then OPENS the site without a problem. Most odd. Thanks again for your reply. Peter.