In the trenches of end-user desktop support, the same problems seem to crop up again and again, regardless of the user, the PC model, or the OS version. In my years of PC troubleshooting, I’ve corrected many perplexing problems and I’ve corrected many more run-of-the-mill problems. This list of common problems and solutions should help you get a jump start on your own troubleshooting efforts.

Common problems for beginners
Many service calls end up being training sessions rather than repair jobs. That’s because beginners often have problems due to a lack of experience and immediately jump to the conclusion that the computer is broken. Here are a few of the most common complaints, which I try to handle over the phone during the initial consultation rather than making a trip out to the site.

  • “The taskbar is gone.” Often, the user has accidentally resized the taskbar to where it’s just a thin bar across the bottom of the screen. Explaining how to resize it usually corrects the situation.
  • “My program is gone.” When I hear this complaint, I suspect the user has deleted a shortcut from the desktop and doesn’t realize that he or she can start the program using the Start menu. Alternately, the user may have accidentally deleted the program’s shortcut from the Start menu. Try walking the user through re-creating the shortcut.
  • “My documents are gone.” This usually signals that the user is in an application program, such as Word, and has always stored his or her files in the My Documents folder. Someone may have changed the file location that appears in the Open dialog box, and the user doesn’t know how to change folders. Give the user a quick tutorial on file and folder locations, and he or she will probably find the missing documents.
  • “I can’t find the files I unzipped.” Here, the user has used WinZip or some other unzipping utility to extract files from an archive but didn’t pay attention to the folder name to which the files would be extracted. Either ask the user to unzip the files again and note the location or use the Search (or Find) command to locate the files if their names are known.

Startup problems
“Won’t start” is a very broad topic; the cause can be anything from the monitor being turned off to a bad DLL. Here’s a further breakdown with some ideas for troubleshooting each situation.

No video
One of the hardest problems to solve is when you don’t get video after turning your computer on. After all, it’s kind of hard to read any error messages that appear on-screen without any video display. Here are some things you can check when you’re not getting any video at boot-up:

  • Make sure the monitor is turned on, plugged in, and connected to the PC.
  • Verify that the computer is turned on and plugged in and all connectors are snugly in place.
  • The PC’s power supply fan should be working, and the drives should be spinning.
  • Sometimes, a reversed hard disk cable or drive jumper conflicts can prevent video from appearing on-screen. You can disconnect all the drives except the floppy and then add the other drives back in, one at a time, until you see some video.
  • Remove the cover. Is the CPU fan working? Is there anything noticeably wrong, like a melted chip, an odd odor, or smoke?
  • Make sure the video card is firmly seated. If it’s a PCI card, try placing it in a different slot. (With an AGP card, you can’t do this, however, since there’s usually only one AGP slot.)
  • Remove all circuit boards, drives, etc. so you’re left with only the motherboard, processor (with fan), memory, keyboard, and video card, and restart the system to see if the video displays. If the monitor displays video, start adding pieces back in, one at a time, until you find the problem component.
  • Still no video? Try a POST tester card, an essential tool for the serious troubleshooter. It’s a circuit card with lights or an LED that fits into an empty expansion slot and provides a code telling you at what point the boot process is hanging.

Windows won’t start
Suppose you get video to display on the monitor, and you can get into the BIOS, but Windows won’t start. The problem could be many things. To find the fix, check out these potential causes:

  • Make sure the hard disk that contains the Windows OS is functional. See my article “Troubleshoot hard drive failures in seven easy steps” for details on how to make sure the BIOS recognizes the drive and that the drive is correctly partitioned and formatted.
  • If Windows is installed on a different drive than the boot drive, make sure the boot drive is functional too.
  • If Windows begins to start but then hangs, a specific driver or DLL is probably causing the problem. If you are using a version of Windows that allows you to start with step-by-step confirmations, do so, and make a note of the last line that appeared on-screen before the hang. Then, start in Safe Mode and remove the program that is causing the problem or use MSCONFIG, the System Configuration Utility, to exclude that item from startup.
  • If Windows locks up at the point where the chosen video mode kicks in—that is, after the splash screen but before you see the mouse pointer—an invalid video mode has probably been chosen. Start in Safe Mode and change the video to a relatively conservative setting, such as 256 color, 800 x 600 pixels, with Adapter Default for the refresh rate.

Windows starts but with errors
Sometimes, an error will appear during Windows startup that allows you to press a key to continue. Then, startup completes normally. Some users ignore such error messages ad infinitum, and that’s certainly one option, but it’s better to get rid of the error.

Such errors are typically caused by a corrupted or missing DLL. For example, suppose a user had a scanner with a driver that loaded at startup, but then he removed the scanner and its software. However, for some reason, the Registry never got the message, and now it still tries to load the scanner driver at startup. To correct the problem, check the Startup folder and Add/Remove programs to make sure the scanner software is not still installed. Then, use MSCONFIG to exclude that driver’s line from startup.

MSCONFIG is an invaluable utility. To use it, go to Start | Run and then type MSCONFIG. It looks different depending on the Windows version; the Windows XP Home Edition version is shown in Figure A.

Figure A
Notice that you can choose Selective Startup to help locate the cause of a problem. You can access this utility from Safe Mode, so you can use it to troubleshoot problems that prevent Windows from starting normally.

Each of the other tabs enables you to deselect individual lines in the startup routine. For example, the Startup tab shown in Figure B lists all the programs and utilities that are set to automatically load at startup. You can deselect a line and then try restarting Windows again to see whether that line was the root of the problem. If it wasn’t, come back to MSCONFIG, reselect it, and try deselecting something else.

Figure B
You can also disable items in the Startup tab by removing their shortcuts from the Startup folder on the Start menu.

Crashes, freezes, and Blue Screens
Suppose Windows starts normally but then starts crashing, freezing, or giving serious error messages shortly afterward. This can be one of the most annoying occurrences when trying to get Windows to run properly. It can mean many different things. Try the following approaches to diagnose and fix the problem:

  • Run ScanDisk (or Check Disk in Windows XP). This will fix about 85 percent of the problems that end users have with Windows.
  • Check for signs of overheating. Random lockups that start several minutes after you start up the PC are often the result of the processor cooling fan not doing its job. Overheating can also result from missing back plates behind expansion slots or from operating the PC with the cover off.
  • If you get a Blue Screen error that reports a problem with a specific memory address and it’s the same every time, use a diagnostic program to check the RAM for errors. Bad memory could cause Windows problems.
  • Try to determine whether the error is the result of a specific action, such as launching a particular program. If it is, see the following section on “Problems with a specific program.”
  • Check for viruses. It’s worth the few minutes it takes to do this, but make sure you have updated the virus definitions first.
  • If you can get to the Internet, try using Windows Update to see whether there are any new patches available.
  • Check the Microsoft Knowledge Base to see whether there are any known issues that could be causing the problem.
  • Reinstall Windows. The quickest way to do this is to reinstall over the top of the existing copy; then you don’t have to reinstall any applications. If that doesn’t solve the problem, try installing Windows into a different folder. I usually rename the old Windows folder to something like Winback, so I can continue to use the name Windows for the folder containing the OS files. I also try to delete everything in the root folder before installing to a new folder. This is easier in some OS versions than in others; you’ll probably need to boot from a startup disk and use the ATTRIB command to remove the read-only and hidden attributes from some of the files there.

Author’s note

You would think that having more air in the case would not be a cause of overheating, but it often is. This is because the case is designed to pull air in from the power supply fan and force it through the case in a certain path. If the case is open or there are extra air holes, such as missing back plates, the air doesn’t flow properly.

Problems with a specific program
If a problem occurs only when starting or using a specific program, here are some things to look for. I have arranged them in the order that I would try them:

  • Verify that the shortcut you’re using to start the program points to the correct file to start the program. If you have upgraded to a new version of the program, this may be where your problem lies. The shortcut might still point to the previous version.
  • Run ScanDisk (or Check Disk in Windows XP).
  • Run the Disk Defragmenter.
  • Turn off any programs running in the background, particularly antivirus programs.
  • Before launching the program you are experiencing problems with, use the Task Manager (or the End Program dialog box in Windows 9x/Me) to see whether there are any programs or processes that are not responding. I have run into situations where a program that loaded at startup would stop responding shortly after startup but not show any evidence of it until it caused a seemingly unrelated program to crash when launched.
  • Disable as many of the programs that load at startup as possible and then restart the computer. Then, try running the application again. If that doesn’t help, try running the application in Safe Mode. If it works, you at least know the program itself is okay and the problem is being caused by a conflict with something loading at startup.
  • If the program doesn’t work in Safe Mode, try uninstalling and reinstalling it. Before you do, however, make sure you have a full set of installation disks for it, and if you have an upgrade version, make sure you also have a full previous version.

Modem and Internet problems
I also frequently see problems involving Internet connections. Modems seem to give end users a great deal of trouble. Here are some ideas for troubleshooting both modem and network-based Internet connectivity.

Network-based Internet connections
In a corporate environment where Internet access is provided through the network, verify the following:

  • Can this computer view other computers/servers on the network? In other words, is the Internet access the only problem here, or is it a general network problem?
  • Can other computers in the same workgroup or domain access the Internet? If so, you know the problem is localized to this PC only. Try running the Internet Connection Wizard in Windows to refresh the settings.

On a small-office-based PC, network Internet access might exist with a cable or DSL connection. In such situations, here’s what I recommend:

  • Check the documentation or setup kit for the cable or DSL service to see whether a specific IP address or computer name must be used. With my cable Internet service, for example, it works only if I specify a certain computer name.
  • Turn off the cable or DSL terminal adapter, wait a few seconds, and turn it back on again. It should resynch with the network within a few minutes. On most models, you can tell it has resynched because a row of lights will illuminate. If it’s still working on synching, most of the lights won’t be lit, and one or more might be flashing. If you can’t get it to synch, the problem lies with the network, not with your PC.
  • Run the Internet Connection Wizard in Windows (going through Internet Properties in the Control Panel is one way to do this) and make sure Windows knows you intend to connect through a LAN rather than through a dial-up.
  • If you have both a dial-up connection and a LAN-based one and are plagued by constant Connect dialog boxes popping up when you are already connected via LAN, go to the Connection tab in Internet Properties and make sure Never Dial A Connection is selected.

Dial-up connections
Here are some tips for troubleshooting a dial-up connection that won’t dial, won’t connect, or won’t stay connected:

  • Check the modem. To do so, use the Diagnostics (or More Info) in the Modems properties of Control Panel.
  • Make sure the correct driver is loaded for the modem. Remove the modem from the Modems properties or from the Device Manager and let Windows redetect it. I recently had a client who bought a new modem (same brand, similar model) without removing the old modem’s driver in Device Manager. Although Windows saw the new modem, it wouldn’t talk to it. A new driver specifically designed for the new model solved the problem. Also, make sure the driver you are using was designed for your OS version.
  • Check the phone line by plugging a telephone directly into it to see if you get a dial tone.
  • Make sure that you don’t have the line and phone cables reversed if the modem has two plugs in the back. Some modems will work with this reversal but will be plagued by static and poor connection quality that can force the modem to drop to a 28.8 or slower connection.
  • If line noise is a problem or you experience slow connection speeds, have the phone company check the line. Slow connection speed is often the result of a noisy phone line rather than a problem with the modem or computer.
  • If the modem won’t stay connected to your ISP or online service, wait 24 hours before assuming there is a problem on your end. Sometimes, ISPs have intermittent connection problems that resolve themselves within a day or so.

This compilation is comprised of just some of the troubleshooting techniques I use for solving the desktop problems that my end users regularly complain about. Use these lists as a quick reference tool to track down and fix some of the problems your users encounter.