Cannot update OSX

Connect to the Internet? When you open Safari are you online?

 

If so, try manually downloading the update(s) to see if it's a problem with the connection to Apple. Also, if the internet is working then find and delete com.apple.SoftwareUpdate.plist from the Preferences folder.

 

Connected to internet, but no Safari and no Software Updates

I recently changed ISP and set up my router. Since then I can connect to the network and Firefox works fine surfing the net. However neither Safari nor Software Updates can connect. It is driving me crazy. I get this error message in SU: Software Update can't check for updates because of a network problem.

I have tried turning off the firewall, deleting plists and restarting. Any other ideas? Much appreciated - thanks

 

Try going to System Preferences > Network > Advanced > Proxies, and make sure that all of the checkboxes next to the proxies are unchecked.

 

Worked for Me

I was having the same issue, which felt like it came out of the blue.

Firefox worked but Safari, iTunes, Software Update and Lotus Notes were not functional. Thanks for the help.

 

Your ISP is probably using http proxies. Firefox can, often, autodetect them while the other software listed are probably using the system defaults. Contact your ISP to determine what network changes need to be made.