Why Is My PC Behaving Strangely?
Does Windows, or an application, crash frequently? Your first step should be to determine whether the problem is repeatable, and to make a note of the actions that led to the crash. Write down the sequence of events, and the contents of any error messages or dialog boxes, then head directly to the software maker's Web site. A patch or an update for the program that can solve the problem may already exist. If one doesn't, you can search for a workaround in the vendor's knowledge base (or conduct a Web search on the product name and symptoms).
Windows' Event Logs record details about many system and application crashes. Right-click My Computer, and choose Manage. Expand Event Viewer in the left pane, and click Application (on most Windows XP PCs, the Viewer keeps three logs: Application, Security, and System). Any recent, repetitive log entry that has a red X next to it means that Windows recorded a serious problem.
If you double-click the log entry, an Event Properties dialog box with more information will appear, though deducing the meaning of an entry can be hard. If you can't decipher the codes, go to EventID.Net, a Web site where users post their own experiences--and solutions for--locating a problem's source (see "Decoding Event IDs Online"). A three-month subscription, which gives you access to detailed solutions and other useful information, costs only $9.
Does your software seem to have a mind of its own? If your home page keeps changing, if pop-up ads appear even when the browser is closed, or if icons appear mysteriously on your desktop, odds are good you're infected with some type of malware, such as spyware or a virus. In this case, the diagnosis is the same as the fix. First run a virus scan. If you don't have any antivirus software installed--and shame on you if you don't--try Trend Micro's free Housecall, which scans for both viruses and spyware. If you already have an antivirus tool but want a free spyware buster, download Microsoft Windows Defender (formerly known as Microsoft Windows AntiSpyware).
Once your PC is clean, make sure your Windows security patches and settings are up-to-date. The free Microsoft Baseline Security Analyzer (or MBSA) will tell you what Windows patches are missing and what settings need to be changed. For more on preventing attacks, read October 2004's Security Tips article, "Keep Viruses, Worms, and Spyware Off Your PC."
Do your input devices flake out? If you're having trouble with a wireless keyboard, mouse, or other input device, first check the batteries. If they're rechargeable, give the device some time to juice up, and then reboot the PC.
But what if the device is wired, or if batteries aren't the problem? Use Windows' troubleshooter wizard for input devices: Click Start, Control Panel (or in Category view click Start, Control Panel, Printers and Other Hardware), and then select either Mouse or Keyboard; next, click the Hardware tab, and then the Troubleshoot button. In addition, the DirectX diagnostic tool can give an input device a pass/fail grade: Click Start, Run, type dxdiag, and then click OK. Check the Input tab for the test results on all your input devices.
If neither the troubleshooter nor the DirectX tool points to a solution, and you have (or can borrow) a standard PS/2 mouse or keyboard, do so; then head to the manufacturer's Web site and download a new driver set for the balky device.
Has the PC gone silent? Make sure the computer's speakers are powered on and properly connected. Launch Windows Volume Control (go to Start, All Programs, Accessories, Entertainment, Volume Control) and determine whether the check boxes labeled Mute are selected. If they are, or if Mute All is filled in, that's your culprit; to fix it, simply uncheck the box. Problem still not solved? Find out if the correct sound source is being called (some computers have more than one audio device). In the Volume Control applet, select Options, Properties and make sure the item listed in the Mixer Device drop-down menu is your sound source (whether it's integrated or an add-in card).
Some other options to consider: Are your headphones or speakers plugged into the correct port? Is the audio cable loose or the audio connector bent? If you hear intermittent sound when you jiggle the connector while it's plugged in, the plug on the headphone or speaker cable is probably bad. If the audio jack wiggles when you remove or insert a plug, the actual jack on the back of a PC might be broken; in that case, a new sound card is the only fix. (If you're using integrated sound, that means buying either an add-in card--as long as you have a slot available to install it--or a new motherboard.)
If you installed hardware or software immediately before this problem started occurring, you might need to reload your sound drivers. Check the sound card manufacturer's Web site, or Windows Update (in the Optional Hardware section), for updates.
If all else fails, you can try to use System Restore, which comes with Windows XP, to return your machine to a previous, functional configuration. Select Start, All Programs, Accessories, System Tools, System Restore and choose Restore my computer to an earlier time. Windows automatically creates restore points (a minimum of one per day), so if System Restore works (which isn't always the case), you should be able to roll back your computer to a time when it worked properly.