Richard has a friend who's Mac is running slower. Is that because her machine is getting older? Leo says maybe, but it may also be that her hard drive is getting less reliable. As the hard drive gets older, it starts to have to work harder to process data. It begins to cache data more. So replacing the hard drive, especially with an Solid State Drive, can make a world of difference in speed. Updating your OS can also help, though if it's too old, you may not upgrade to the latest (El Capitan). Leo says there's a few easy things to do like resetting your browser and clearing the cache. History Menu - Clear History and Website Data. The next step is to reinstall the entire OS. Backup your data, format the hard drive and then run reinstall. Another easy thing to do is run Apple's First Aid utility. It will check the hard drive and fix any problems.