All, My hard drive failed so I replaced it with a crucial mx300 525gb. Now, whether my new or old hard drive is in, I cannot connect to web pages as it says the site is insecure/certificate cannot be trusted. I can't connect to iCloud because it says it can't establish a connection with the server. Apple has been unable to permanently solve so I'm asking here. Below is everything I've tried already. -wipe drives, partition etc -reset nvram/smc (allowed my computer to work for about 20 min before going back to this issue now won't fix it again) -time/date check and reset -reinstall OS X sierra (online and from the store) -reinstall OS X Yosemite -change startup disk It has been an ongoing issue for about a week and nobody can seem to figure it out. Any ideas?