Guide · 5 min read
Why your computer keeps freezing
Computer freezing or locking up? Learn the common causes - overheating, failing drives, memory faults, drivers and software - and how to narrow them down.
A computer that freezes is more than an annoyance. The mouse stops moving, the screen locks, unsaved work disappears and you are left holding the power button. Occasional freezes can be caused by a single misbehaving program, but freezes that keep happening usually point to something specific in the hardware or software, and that kind of fault rarely goes away by itself.
This guide explains how to tell the difference between a program that has hung and a computer that has frozen, the common causes of each, and the checks you can safely run yourself. Paying attention to when and how the freezes happen is the most useful clue you can give anyone who ends up repairing the machine.
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Quick checklist
- Check whether the mouse still moves when it freezes
- Note what you were doing each time
- Back up your files straight away
- Clear dust from vents and use laptops on a hard surface
- Run Windows Memory Diagnostic
- Update or roll back graphics and wireless drivers
- Unplug USB devices and test again
A frozen program or a frozen computer?
If one window shows Not Responding but the mouse still moves and other programs work, the problem is that program, not the whole computer. On Windows, open Task Manager with Ctrl, Shift and Esc and end the task. On a Mac, use Force Quit from the Apple menu. If the pointer will not move, the keyboard does nothing and even Ctrl, Alt and Delete fails, the whole system has locked up, which points to a deeper cause.
Notice the pattern
Freezes rarely happen completely at random. Note what you were doing each time and look for a common thread. A freeze that only happens once the computer is warm points to heat, while one that started after an update points to a driver or software conflict. Write the details down as they happen, because a few notes are far more useful to a technician than a general sense that it locks up sometimes.
- Only when a particular program is open
- After the computer has been on a while and is warm
- When plugging in a USB device or docking station
- Right after an update or new software
- When opening large files or many browser tabs
- At startup, before you have done anything
Overheating
When a processor gets too hot, the computer first slows itself down and may then freeze or switch off to protect itself. Laptops are especially prone, because their small fans and vents clog with dust and lint. If the fans run loudly, the base feels very hot, or freezes only start once the machine has been working hard, heat is a strong suspect. Use the laptop on a hard, flat surface, keep the vents clear and have the inside cleaned if dust has built up.
A failing storage drive
A drive that is starting to fail often struggles to read certain areas, and while it retries, everything else waits. The computer may stall for a while and then carry on, or lock up completely. Clicking sounds from a desktop, very slow file opening and error messages about the disk are all warning signs. Back up your files immediately if you notice any of these, because a failing drive can stop working altogether with little further warning.
Memory faults, drivers and software
Faulty RAM causes freezes and blue screens that seem random. Windows includes a Memory Diagnostic tool you can find from the Start menu, and it is worth running when freezes have no obvious pattern. Outdated or corrupted drivers, especially for graphics, wireless and docking stations, are another common cause, as are two security programs clashing with each other. If freezes began after a specific update or install, try removing that change or rolling the driver back. Keep only one antivirus program running at a time, and get drivers from the computer maker's support page rather than third-party download sites.
Power and peripherals
A failing power supply in a desktop, or a worn laptop charger, can cause freezes and sudden restarts when the computer is working hard. Faulty USB devices and cheap hubs can also lock the system up when they are plugged in. Try unplugging everything except the keyboard and mouse and using the computer normally for a while. If the freezes stop, add devices back one at a time until the culprit shows itself.
When to call a technician
Book a technician when freezes keep happening after these checks, when you hear noises from the drive, or when the computer locks up during important work. We run hardware tests on the drive, memory and temperatures, read the system logs for the errors behind each freeze, update or repair drivers and clean out overheating parts. If a component is failing, we protect your files first, then replace it.
From $135 + GST + $30 call-out ($185.25 incl. GST)
Related services
Computer & Laptop RepairSlow, broken or virus-ridden? Fixed onsite where we can.Computer Health Check & Tune-upA full check of a computer's drive, updates, security, startup items, backups and cooling, with a written list of findings.Software Installation & TroubleshootingPrograms installed, licensed, updated and repaired, with junk software removed and error messages tracked down.Common questions
Is it bad to hold the power button when my computer freezes?
It is fine as a last resort, but it can corrupt files that were open and, done often, can damage the operating system. Wait a little, then try Ctrl, Alt and Delete or Force Quit first. Only hold the power button when nothing else responds.
Can a virus make my computer freeze?
It can, though it is less common than heat, drive or driver problems. Malware running in the background can use up the processor and memory. Run a full scan with your security software, and look for other signs such as pop-ups or programs you did not install.
Why does my screen freeze while the music keeps playing?
That usually points to the graphics side of the system, such as a crashed graphics driver, rather than a total lockup. Updating the graphics driver from the computer maker's support site is a sensible first step. If it keeps happening, the machine needs a closer look.
Will reinstalling Windows stop the freezing?
Only if the cause is software. A clean reinstall clears corrupted system files and conflicting programs, but it will not fix a failing drive, faulty memory or overheating. Test the hardware first so you do not go through a full reinstall for nothing.
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