Do you get the multi-coloured 'spinning wheel of death' regularly? Is the whole thing running slowly? Does it take forever to open webpages or to open any file at all? These are symptoms of an unhappy computer, the cause can be various things.
The first thing to do is some basic trouble shooting and maintenance, beginning with a
Restart and Zap the PRAM:
(Parameter RAM is a cache where settings are stored which can become mildly corrupt and cause problems. Some minor glitches can be sorted by clearing it — zapping it)
1. Restart, and as soon as you hear the start up noise immediately hold down the 4 keys: Apple+Option+P+R on the keyboard.
2. Wait until the Mac makes a second start up noise a few minutes later, keep holding until it has made 3 extra start up noises then let go all the keys and it will strat up as per usual.
3. When it has started up go to Applications/Utilities and open Disk Utility. Select your hard drive icon on the left and click the button called Repair Disk Permissions.
After all that if there is no improvement you will need to one of two things:
1. On older computers, locate the install disk that you received with the computer. If there was more than one disk it is Disk 1 that you need.
Pop it into the machine and Restart the computer from the Apple menu top left and as soon as it goes black before it boots up again hold the C key down. This will tell the computer to run from the operating system on the disk rather than the operating system on the computer, so that diagnostics and repair can be attempted on the internal hard drive.
2. One current and recent computers with no disk, Restart the computer from the Apple menu top left and as soon as it goes black before it boots up again hold the Command and R keys.
1. On older computers, the computer will start and eventually offer a page that prompts you to choose English as your language. Next page will say Preparing for Installation. Ignore it and go up to the Utilities menu at the top of the page and choose Disk Utility. It will open same as it did on the computer when you zapped the PRAM in the previous step, but this time it is running from the disk so it can Repair the hard drive which is currently not being used. Image below.
2. One current and recent computers the computer will start and eventually offer a page that prompts you to choose English as your language. Then you will get a choice of a few options. Select Disk Utility:
Usually there are only minor repairs required which you will see as red text in the repair window and it will fix them OK.
Once it has finished, quit Disk Utility, quit the installer (Command+Q) and choose Restart from the Options offered and the computer will restart as normal.