macWorks Disclaimer: Some people have been able to upgrade to Sierra/HighSierra with no problems or issues. Others have noticed a big slowdown after the upgrade. If you have problems after an upgrade, please let me know. We can do a clean install which will fix any issues.
Background: Even though Apple has suggested since Lion was released that you can “upgrade” to their newest operating system or OS, it has always been a best practice to do a clean install.
When you upgrade, you install the new OS on top of the old OS, which can create problems. When I clean install, I erase the hard drive and install nothing but the new OS.
You can’t really hurt anything by trying the upgrade, so here’s how to do it:
Before you upgrade, please do the following:
1) Go to App store and make sure all other software updates are done except for Sierra, of course. You may have to check several times by going to App store, then click on Updates.
2) Run Disk Utility > both Repair Disk Permissions and Verify Disk.
3) Run all the Cocktail checks, then restart the Mac.
4) Make sure Time Machine has a current backup, it would ALSO be good if you can use SuperDuper to get a second compete backup of the Mac.
5) Make sure all programs are closed, so the only light on the dock will be for Finder, then go to App store and click the update for Sierra. It’s about a 5+ gig download, so may take some time just to download. After it’s downloaded, just run the Installer which will be in your Applications folder.
6) After the Sierra upgrade is finished, recheck updates from the App store at least one more time, then run Disk Utility again > Repair Disk Permissions.