When a Mac starts acting strangely, the first thing our support desk asks is when it was last restarted. It’s the oldest line in IT support (The IT Crowd made sure of that), and it’s survived because it works far more often than it has any right to. Here’s what a restart actually clears, when it’s worth shutting down instead, and the one setting that can quietly undo the whole thing.
What builds up while your Mac is running
A Mac that’s been on for a few weeks is carrying a lot of state. Every app you open starts processes, and behind them sit dozens of system services handling Wi-Fi, Bluetooth, iCloud sync, printing and network drives. macOS keeps all of that remarkably tidy, but it’s software written by people, so small things drift over time.
The usual culprits look like this:
- A process gets stuck waiting for something that’s never coming, such as a network share that dropped or a printer that’s been switched off. It hangs on to memory or a file, and anything that depends on it stalls too.
- An app slowly takes more memory than it gives back (a memory leak). After a few days, the Mac starts leaning on the disk to cope, and everything feels sluggish.
- A background service gets confused after the Mac has slept and woken on three different Wi-Fi networks in a week. Bluetooth headphones that won’t reconnect and a VPN that won’t come back up are the classic signs.
- An update has downloaded, but part of it only takes effect once the Mac starts fresh.
A restart closes every one of those processes, clears memory and starts each service again from a clean, known state. You don’t need to work out which of the four went wrong, and that’s why we ask about it first. It takes two minutes and rules out a whole category of problems.
Restart or shut down on a Mac
Older Macs with Intel processors can sometimes benefit from a full shut down rather than a restart. They have a separate System Management Controller (SMC) that looks after power, fans and battery charging, and fully powering off can clear problems there that a restart doesn’t. If a restart hasn’t sorted a power, fan or battery issue on an Intel Mac, a shut down is worth trying next.
On Macs with Apple silicon (M1 and later), it makes no difference. Apple’s support guidance treats Restart and Shut Down as equivalent on these machines and confirms the SMC resets automatically, so we’d just use Restart because it’s quicker.
To check which kind of Mac you have, choose Apple menu > About This Mac. Apple silicon Macs show a “Chip” line; Intel Macs show “Processor”.
If you’ve still got Intel Macs in the fleet, shut down is a sensible next step when a restart hasn’t helped, especially for power, fan or battery behaviour. Honestly, though, the bigger conversation for those machines is replacement, since Apple has confirmed macOS Tahoe was the last major release to support them.
The tick box that can bring the problem straight back
When you choose Restart or Shut Down, macOS asks if you’re sure and shows a tick box labelled “Reopen windows when logging back in”. If it’s ticked, every app you had open launches again when you log back in, including the one that was misbehaving. If you’re restarting because an app froze or the Mac crawled, untick it so you start clean.
One detail catches people out. If you skip the confirmation by holding Option while choosing Restart, or the Mac is forced to restart, macOS uses whatever you chose last time. So if the box was ticked once, it may still be quietly on.
On Windows PCs, Restart is the one to use
Many of our clients run a handful of Windows machines alongside their Macs, and on those a restart is always the way to go. Windows has a feature called Fast Startup, switched on by default, which saves part of the system to disk when you shut down so the PC boots faster next time. That means Shut Down doesn’t give you a truly fresh start, but Restart does.
How to restart properly
On a Mac:
- Save your work.
- Choose Apple menu > Restart.
- Clear the “Reopen windows when logging back in” tick box.
- Click Restart.
- Wait for the login window. Then log in.
If the Mac does not respond:
- Press and hold the power button until the Mac turns off. Unsaved work can be lost.
- Wait a few seconds.
- Press the power button to start the Mac.
On a Windows PC:
- Save your work.
- Select Start > Power > Restart.
When a restart isn’t the fix
A restart clears temporary problems. It won’t repair a corrupt app, a failing battery, a nearly full disk or a setting that’s simply wrong. The useful test is how quickly the problem comes back. Gone for weeks means it was a one-off. Back within a day or two means the restart is only buying you time, and something underneath needs looking at. If you’ve got Macs that need restarting every few days just to stay usable, we’re happy to take a look.
In Dr Logic’s experience, the Macs behind most “it’s just slow” tickets are the ones that haven’t been restarted in weeks. Macs cope well with long uptimes, but a weekly restart lets updates finish and clears out whatever has built up. Friday afternoon, before everyone logs off, is an easy time to make it a habit.
Want to take the stress out of running your own Mac fleet? Speak to us about Apple IT Support for your whole business.
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FAQs
Is it bad to never shut down my Mac?
No. Modern Macs are designed to sleep between uses and cope well with long periods switched on. The downside is that small glitches and memory build-up accumulate over time, and some updates wait for a restart to finish. A restart once a week covers that without needing to shut down every night.
How often should I restart my Mac?
Once a week is a good habit for most people, and whenever macOS asks you to after an update. Restart sooner if apps start freezing, Bluetooth or Wi-Fi misbehaves, or the Mac feels sluggish. If you’re restarting every day or two to keep it usable, there’s an underlying problem worth investigating.
Does restarting my Mac delete anything?
A restart doesn’t delete your files, apps or settings. It closes everything that’s running and starts it again, so any unsaved work in open documents can be lost. Save first, and untick “Reopen windows when logging back in” if you want apps to stay closed after the restart.
Should I use Restart or Shut Down on a Windows PC?
Use Restart when you’re fixing a problem or finishing updates. Windows Fast Startup, which is on by default, saves part of the system to disk when you shut down, so Shut Down isn’t a full reset. Restart always runs a complete boot. Holding Shift while clicking Shut Down also forces a full shutdown.
