need help my mac wont find updates?!

[sako94]

hey guys i have 2 iMacs , both with the same processor speed and everything(got the best one) the problem is my left imac never updates unlike the right one. the right one always finds update to all my applications and i update them so i go on other mac to update it too but it shows everything is up to date, but it is not! it wont even let me open itunes because thats so outdated.

What do you think is the problem? This one has been causing random errors latly and im thinking of taking it too apple but im thinking if i get it replaced, will my registration key for iWork is go away , being forced to buy another one?
Thanks in Advance

 

[angelwatt]

For troubleshooting: open Terminal and give the following command,

softwareupdate -l

That's a lowercase L at the end. This will list available updates, like Software Updates should be doing. If it list updates here (and even if it doesn't) you can try deleting the preference file for software updates to see if it helps. Located: ~/Library/Preferences/com.apple.SoftwareUpdate.plist

 

[sako94]

okay but that didnt really help i think im going to take it to apple. What should i do so i keep iWork on it still? because if i cd download again will i put the same registration code will it work?