Hi guys - Im running a MBA with Mac OS X 10.7.5. I am using the Admin account as my user account My Outlook for Mac was having some issues with searching this morning and looking online it was suggested that the issue was likely to be resolved by reindexing the folder that the identities for outlook are based in (USER>Documents>Microsoft User Data>Office 2011 Identities). I couldnt get it to do this so the next suggestion was to force it to reindex the entire drive. I started this process but it then kicked up another significant issue... I started to get error messages like the below (all the extensions mentioned seem to be apple ones): SYSTEM EXTENSIONS CANNOT BE USED the system extension "/system/library/extensions/appleavbaudio.kext/contents/plugins/appleavbaudioplugin.kext"" was installed improperly and cannot be used. Please try reinstalling it, or contact the product's vendor for an update. [please note that I have just had to type the above message in so the capitals are not all correct etc]. Due to these issues I did a search online and the suggested resolution was to use DISK UTILITY to repair all permissions on the hard disk. I did this but once done I could not even access Outlook, Mail and most Applications (other then Safari). This made the permissions as following for most (if not all files) User - Permisions System - Read&write admin - read only everyone - read only If I tried to access most applications I received an error (slightly different for each application but the gist of them is the same) upon startup saying that I could not use the application as I didn't have permission to access certain relevant folders/files. I have managed to work around this by changing permissions on the hard disk to 'Read&write' for all 3 (system, admin, everyone) then used 'apply to enclosing items...' but obviously this is not ideal for security. After having done this I can now access the applications but the error messages about 'System extension cannot be used' are still happening. I am assuming that either the repair permissions function (or today I manually by accident) have changed the permissions on a vital applications/system folder and stopped the applications having access to files that they need to. So basically I have 2 questions: How can I get the error messages about system extensions to stop appearing? How can I get the permissions to give me access to the applications to ensure I can use them without having 'everyone' set to read&write? Obviously this is not good for security.