My MacBook Air used to be rock solid, but it has grown increasingly unstable over the past year. For example, this afternoon I can't switch to my other user account. I select the account from the fast user switching menu and nothing happens.
Part of me wants to just start over, reinstall and reconfigure OS X and all of my applications from scratch. It would probably solve a lot of problems. But I have so much work invested in my current configuration. It would take days or weeks to fully rebuild.
I'm thinking the next best option would be to wipe the drive and restore my latest Time Machine backup. I know that Time Machine doesn't back up everything — caches, log files, etc. — so maybe restoring from backup would have a "rejuvenating" effect. Or it could just be a complete waste of time.
In general, is reformatting and restoring from Time Machine a good way to get a Mac running like new? Or is it merely "worth a shot"?
Best Answer
I like MK's answer above. Look at those things first.
Then - consider this... I experienced something similar to what you are describing. I tried the erase, format and restore from Time Machine... it didn't really help. Then someone suggested starting up with the option key held down and reinstall the operating system. (this 'reinstalls' the OS while keeping all of your files!)
If you are running Mountain Lion or later, you can follow Apple's instructions here: http://support.apple.com/kb/PH10763?viewlocale=en_US
This solution worked much better for me.