PC freezes: My desktop/laptop PC/computer keeps freezing every 15 minutes requiring a reboot?

PROBLEM: My elderly PC running Windows XP SP3 has 512MB of RAM and an Intel Pentium 4 processor. Of late, the PC keeps freezing regularly, about every 15 minutes, which requires a restart as the only method of recovery. Also, once, recently, it shut itself down. Just before it did so, a message came up saying that a disk error had occurred and that I must press the Ctrl + Alt + Del key combination to restart. Any ideas on what might be causing these occurrences?

ANSWER: There a several possible causes of problems of this kind, which can occur regardless of the version of Windows (XP/Vista/Windows 7/8.1) that is being used.

The most obvious causes are changes you made to the system just before the problems started occurring, and new software device drivers that have been installed. If you made any such changes, reverse them, by using the roll-back driver feature in Windows XP by entering devmgmt in the Run box to open the Device Manager, find the device that had its driver updated, right click on it, click on Properties in the menu that comes up and look under the Driver tab for  the Roll Back Driver button (also applicable to Vista and Windows 7 using the Search… box). The Device Manager has its own icon in the Control Panel in Windows 7 and 8.1. If a program doesn’t have its own uninstall option, you can use Add or Remove Programs in the Control Panel to remove any software that you installed. (Within Programmes & Features in Win7 and Win8.1)

The next most obvious cause is a failing hard disk drive. If the computer’s BIOS setup program has a S.M.A.R.T. setting, enter the BIOS by pressing the entry key(s) at startup (pressing the Del key just after the memory count is the usual method of entry, but it could be a different key (F1, etc) or even a key combination, depending on the make of BIOS), and enable it if it isn’t enabled. This makes software run that monitors the hard disk drive(s). If the hard drive is about to fail, the user should be informed by a message in advance of that happening so that the data on the drive can be saved. It is possible to run software that interprets the data produced by the S.M.A.R.T. software. Use the search query S.M.A.R.T. monitoring software to find it.

Note that Windows 8.0/8.1 computers use a UEFI instead of a standard BIOS that is difficult to access, probably to keep users out of it who will mess their computers up by experimenting with the settings, raising support costs. Here is a video that shows how to access the UEFI settings:

Tutorial: How to access BIOS (UEFI) settings in Microsoft Windows 8.1 –

You should run the free hard-drive diagnostic software that the major hard-drive manufacturers provide from their websites. The table below provides links to many of the download sites of the major hard-drive manufacturers.

Where to download the hard-disk-drive diagnostic utilities for a particular major make of hard drive

MHDD is the most popular freeware program for low-level hard-disk-drive diagnostics. –


Seagate – SeaTools –


Note that Maxtor and Quantum hard drives use SeaTools (above).

Western Digital – Downloads – http://support.wdc.com/product/download.asp?lang=en

Hitachi/IBM – Drive Fitness Test – http://www.hgst.com/support


Note well that if such a utility is used on a faulty system (suffering from bad RAM memory, an inadequate power supply unit, a faulty motherboard, etc.) it would probably produce unreliable results.

If you don’t know the make of the PC’s hard disk drive, in Windows XP, open the Device Manager by right-clicking on My Computer and then click on Properties in the menu that comes up. In Windows XP, do all of that and then click on the Hardware tab, or enter devmgmt.msc in the Start => Run box. The Device Manager is listed in the Control Panel in Win7 and Win8.1.

Click on the + beside Disk drives to reveal the hard drive(s) installed. If the manufacturer’s device drivers are installed, the make and model of each drive listed there should be provided. If the standard Windows drivers are installed, the make and model won’t be provided. In that case, try entering msinfo32 in the Start => Run box in Windows XP. In Windows Vista and Windows 7 enter that command in the Start => Search box. Doing that brings up the System Information window. Look for the information provided on disk drives. In my MSI M662 laptop the entry is Model – TOSHIBA MK1032GSX, which means that Toshiba is the manufacturer.

Alternatively, download and use the free Belarc Advisor from http://www.belarc.com/. When you know the manufacturer of the drive, if you don’t know the web address, enter the name (Hitachi, Seagate, Western Digital (WD), Samsung, etc.) as the search query in a search engine.

If the hard-drive manufacturer’s device drivers are not installed for that particular make/model of drive, you can obtain them from its website. They are installed by double-clicking on the downloaded file. Or, if you have a brand-name computer, you should be able to obtain all of the device drivers from its manufacturer’s website. They are installed by double-clicking on the downloaded file.

Note well that you should back up any files that you don’t want to lose, because running diagnostic software on a failing hard drive can make it fail completely and irrecoverably. Also note well that if such a utility is used on a faulty system (suffering from bad RAM, an inadequate power supply unit, a faulty motherboard, etc.) it could produce unreliable results.

If the hard drive passes the diagnostic tests, you have to find out if the problems are caused by hardware or a software. The freezing problem dealt with on the following computer-forum thread looked as if it was caused by a problem with hardware, but turned out to be caused by a device driver:


The best way to find out if a freezing problem is hardware or software related is to boot the system with a Linux boot disc, which was not discussed in that form thread but is discussed below.

The first action I would take is this: boot the system into Safe Mode by pressing the F8 key before Windows XP/Vista/7 begins to load (use the search query how to enter safe mode in windows 8.1 to find out), and run a tool such as the Disk Defragmenter, which in Windows XP is under Accessories => System Tools. In Windows Vista and Windows 7, to open the Disk Defragmenter enter defrag in the Start => Start Search box to be presented with a clickable link to it. If the problem doesn’t occur, those problems are most probably being caused by software that loads with Windows, because faulty hardware won’t work in Safe Mode.

It is a good idea to have a distribution of Linux, such as Ubuntu, that loads from a CD/DVD. To create an Ubuntu CD/DVD, visit http://www.ubuntu.com/ and download the ISO file, which is a 700MB download. You then burn it to a CD or DVD with disc-burning software, using its burn image option. You can the use the disc to boot the system if the BIOS setup program is set to boot from the CD/DVD drive first (the CD/DVD drive is set as the first boot device). You can install Ubuntu on to the hard disk drive from the disc or just select to run it from the disc itself without being installed. Files are copied temporarily to the hard drive and run.

If you have an internet connection, say to a wireless router, all you have to do in that case is open the Firefox browser, which is part of the operating system, and click the wireless icon that appears at the top right corner of the screen (above Firefox). If the network has encryption security enabled in its setup, it will ask you for the WEP/WPA/WPA2 security encryption key to log on to the network. If security is not enabled, you should just be able to log on without any restriction, which anyone else with a wireless-enabled computer could also do.

If you need to go online, you can use it to download drivers, or run an online virus scanner, etc. If the computer works from the disc without freezing the you can be sure that the problem is a software issue.

Another method is to boot the system to something that is independent of Windows, such as a diagnostics CD, or a boot CD with Linux installed on it, or a BartPE rescue CD. If you have a brand-name PC that came with diagnostic software, run it.

If it doesn’t provide RAM memory tests, you can make use of the Windows Memory Diagnostic tool.

Microsoft Windows Memory Diagnostic utility [Applies to Windows 7] –

“The Windows Memory Diagnostic tests the Random Access Memory (RAM) on your computer for errors. The diagnostic includes a comprehensive set of memory tests. If you are experiencing problems while running Windows, you can use the diagnostic to determine whether the problems are caused by failing hardware, such as RAM or the memory system of your motherboard. Windows Memory Diagnostic is designed to be easy and fast. On most configurations, you can download the diagnostic, read the documentation, run the test and complete the first test pass in less than 30 minutes.” Obtain the full instructions and download from this page. –


Note that a full scan of the RAM memory takes a long time.

You can also download and use Memtest86. Latest version from http://www.memtest.org/ and http://www.memtest86.com/.

The power supply unit might be responsible. There are no checks that anyone who is not an electronic technician can do apart from buying a new unit and trying it instead of the existing unit. Here is the page on power supply units on this website:


It is unlikely to be the cause of the problem because of the regularity of the freezes, but you should open the case and check that the heatsink-and-fan cooling unit that is fitted over the processor is working properly. It could be clogged with dust or it could be malfunctioning and causing the processor to overheat and cease working after 15 minutes. It could be cooling down sufficiently in the time it takes to reboot. You can buy new cooling units. They are easy to remove and install. Just make sure that you buy a cooler that is designed to work with the make/model of processor. To find out where you can buy them, just enter a search query, such as pentium 4 cooling units, in a search engine. Pentium 4 processors are Socket 478 or Socket LGA775. You can find out which socket your PC’s motherboard has by consulting its user manual, which can be downloaded from its manufacturer’s website.

Depending on how much you use the computer, you should replace the cooling unit periodically. They can last up to five years or longer on a computer that is in regular use, or they can fail after about 18 months, depending on the quality of the unit. I use only quality units, so I replace them after about three years of use. If you don’t make much use of a brand-name computer, you should only need to clean the cooling unit and inside the case once a year.

If you don’t know the make and model of the motherboard installed in your computer, the Belarc Advisor creates an analysis of the hardware and software on a personal computer. Look under FREE DOWNLOAD – http://www.belarc.com/.

You should remove the dust from inside the case periodically by using a can of compressed air that can be obtained from good computer shops. It’s not advisable to use a vacuum cleaner on suck because of discharge static electricity can destroy electronic components. I have used a vacuum cleaner on blow and a hair dryer without any problems.

If faulty hardware is not the cause, a virus, malware and the start-up programs are the most probable causes. I use the Malwarebytes Pro comprehensive malware scanner. A licence for 3 PCs costs less than £20. Very good value for money. I don’t use a free malware scanner any more because they hog system resources and annoyingly produce messages asking you to upgrade to the paid-for product. Make sure that the have the latest updates installed for your scanner(s) before launching scan(s).

If you are using Windows XP, enter xp unnecessary services, as the search query in a search engine to find information on how to disable unnecessary services. Replace the xp with vista or windows 7 (or win7) or Windows 8.1 (Win8.1) in the search term if you are using Windows Vista or Windows 7/8.1.

In Windows, you can experiment by disabling the start-up programs (under the Startup tab) by entering msconfig in the Start => Run box (XP) or the Start => Start Search box (Vista) or the Start => Search programs and files box (Windows 7). In Windows 8.1, use the Task Manager to manage startup programs. If the problem disappears, isolate the culprit by re-enabling them one at a time until the problem reoccurs.