Thousand Oaks
Personal Computer Club

Question: What causes my screen to freeze up? I tried pressing "Control/Alt/Del" but nothing happened. I had to press "Restart" and that worked, but this has happened several times recently. What is causing it?

Answer: Many things could be causing it.

1. Overheating - If your PC is getting overheated, that may cause problems. I had a server at work that kept freezing up and it turned out that the little fan inside that cools off the CPU chip wasn't working well and the microprocessor was overheating. Take the case off your computer, turn it on, and see if both the CPU fan and the power supply fan are turning.
2. If the computer freezes only when you run a certain program, try uninstalling and re-installing the program.
3. Running Scandisk may help. If there are errors on the hard drive, then you program may freeze whenever it uses information on parts of your hard drive that have errors. Scandisk is found in "Start | Programs | Accessories | System Tools". For details on running Scandisk, check the "Tips" part of our web site.
4. Power surges or brownouts can cause a bit in memory to get switched the wrong way causing your program to freeze. Make sure your computer is plugged into a good surge protector. Even better (but more expensive) is a "UPS" (uninterrupted power supply).
5. Some memory on your computer may be going bad. I had this happen on one of my old computers. I kept getting the same errors over and over. After lots of troubleshooting (I even reformatted the hard drive and reinstalled the operating system), I replaced the memory and it's running fine now.
6. If your computer freezes before it even finishes booting up, you may be low on RAM (random-access memory). If your computer used to boot up OK, but now it doesn't, maybe another program is now running during startup that wasn't before. Try booting your computer in Safe Mode. To do this, turn on your computer and press [F8] immediately when you see "Starting Windows 95/98". A menu should be displayed where you can choose "Safe Mode". If your computer boots up in Safe Mode, check "Start | Programs | Startup" to see what is loading. Uninstall or disable any programs you may not need.
7. If too many programs are loading into memory, there is another way you can disable some programs from loading. Click "Start | Run", type "MSCONFIG", and press ENTER. Click on the "Startup" tab. Everything that loads will have a checkmark. Uncheck most of the programs and see if the problem continues. If it doesn't, recheck one program at a time to see if you can eventually isolate the offender.
8. Sometimes, your computer will just freeze for no reason in particular. I took a Computer Architecture class at Moorpark Collage many years ago. One thing that I learned from the class is that your computer is not perfect and will make mistakes. There are millions of circuits in your computer that are controlled by electricity. Electricity isn't perfect. To quote from my textbook: "Computer memories can make errors occasionally due to voltage spikes on the power lines or other causes. To guard against such errors, most memories use error-detecting or error-correcting codes." So most of the time, the computer will catch the errors. However, I can imagine that every so often the computer will miss one of the errors and if your computer accesses that part of memory with the error, it will freeze.

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