Oh, No--My PC Won't Even Boot!
Do strange sounds emanate from your PC? Some sounds can indicate serious problems. If you suspect the hard drive is on its last legs, the safest thing to do is to shut down the PC immediately. To find out if the drive is causing the noise, disconnect the drive's power cable before turning the computer back on.
If the hard drive is the noise source, your next step is to download a utility that can read the SMART (Self-Monitoring Analysis and Reporting Technology) diagnostic codes off the drive; SMART data can tell you precisely what's wrong. Get the one made by your hard drive's manufacturer: Point your browser here for a link to your drive maker's SMART utility download page.
Does the noise persist, even with the hard drive disconnected? Pinning down the problematic component is a bit harder--but at least you can take comfort in the fact that your data isn't about to kick the bucket. One way to troubleshoot is to use the low-tech (yet effective) cardboard tube method: Hold one end of a paper-towel tube to your ear and the other end to various system components, and listen.
Is the sound coming from a fan?If you are concerned about an unusual fan noise, use the free SpeedFan tool (see "Monitor Your Fan Speed") to see if a cooling fan attached to the motherboard is spinning too slowly. Some components will fry themselves if not cooled, and a new fan costs far less than a new CPU or graphics board. Another good (and no-cost) utility for monitoring system heat is CPUCool.
Got beeps? If you hear an unusually long beep (or several beeps) when you first power on the PC, your system is trying to tell you something--and it's not good. While the normal beep before boot-up--a single short tone--is a universal "all okay" signal, the more elaborate diagnostic beep codes aren't standardized; they vary by BIOS manufacturer and are sometimes customized further by motherboard makers. You'll have to look up the meaning of a specific beep pattern. On Dell Dimension XPS Dxxx systems, for instance, one beep followed by a pause and then two more beeps means that the graphics card isn't functioning correctly (maybe it's not seated properly).
Your PC vendor's support site should have a directory of its BIOS beep patterns, so that's the first place to go. If you can't find the information there, check out BIOS Central for an encyclopedic listing of beep codes and their meanings, organized by BIOS manufacturer. In addition, some vendors (including Dell) place diagnostic lights on the back of the computer case that give you a more detailed report about what's wrong. Meanings vary by system design, though yellow lights are usually a bad sign. Check your vendor's site for details.
Could a hardware problem be the source of your boot-up woes?If you recently added new internal hardware, such as more memory, it's possible that a component is seated incorrectly in its slot or that you bumped another component or cable, loosening its connection. It's also possible that the new component is either broken or incompatible with the PC.
Start by turning off and unplugging the computer, grounding yourself by touching a metal part on the outside of the PC's case, and then opening the case. Once inside, check that all the internal cables are connected properly. Also, ensure that each internal card and RAM module is properly seated by gently and evenly pressing along the length of the card or DIMM. If it doesn't seem to move when you apply pressure but you still feel uncertain about the seating, remove the card or DIMM entirely, and reseat it again. When you're done, put the PC back together, reattach any disconnected cables, and fire it up.
Even if the RAM modules are seated correctly, the system memory may still be the source of the problem--if the RAM has gone bad. Use the free Memtest86 utility to create a bootable CD-ROM that checks for memory failures. This tool performs detailed tests (and can catch problems that basic BIOS memory checks often miss).
In rare instances, a computer won't boot because of a hardware conflict between a new component and the rest of the system, or because the new component is simply not working. While this happens most often with older PCs, it can occur with almost any upgrade. To test this possibility, remove the new part and put the old one back in. If the PC boots up fine, you have a problem component. Get in touch with the component's manufacturer for additional instructions.
Sometimes a computer can get all the way to the normal startup sound that plays when Windows loads your desktop, but you see no image on your monitor. That's a sign of a problem with either your graphics board or your monitor. First check for a loose monitor cable, and for broken or bent connector pins. If everything appears normal, attach the monitor to another PC to test it. If it works, try hooking up a different monitor to the balky system. If you still get no picture, that indicates a loosely connected or bad graphics board, so power down the PC, open the case, and make sure the card is seated properly. (If you have integrated video and it is malfunctioning, you'll probably need a new motherboard.)
Does some text appear on screen, after which the PC stops responding? If your machine's startup screen is reporting an error code--also called a BIOS Power-On Self Test, or POST, code--you can look up its meaning in your motherboard manual or at BIOS Central.
If you see a 'Non-System disk...' boot error message (and no disks are in your floppy drive), unplug any external hard drives and remove any CDs from the tray, and then reboot the computer. If the problem persists, the hard disk's boot sector or partition table may be corrupted. The $39 Partition Table Doctor 3 can rebuild the partition table, a remedy that in some cases will restore a faltering PC to a fully working state. The program is available as an ISO file, which you can use (on a working system) to make a bootable CD.
Does your screen go entirely blue and display a few lines of text at the top? Congratulations--you're experiencing Windows' notorious Blue Screen of Death. And you're blue, too, because the cryptic error messages (for example, 'STOP: 0x0000021a Fatal System Error') that appear on BSODs aren't very helpful. You can sometimes get useful information about them by performing a Web search for the message using a working PC. Write down the Stop Error code that appears (ten digits starting with the number zero and the letter x); to decode the message, visit Common Stop Messages. You can also uncover a wealth of info via a search engine.
But what if Windows reboots as soon as the Stop Error pops up? Some genius thought it would be a good idea for Windows XP to automatically reboot whenever it crashed. Obviously, that engineer never conceived of a situation where the crash occurs during the boot sequence. For XP users that means the PC enters an endless loop of crashing, rebooting, and then crashing again--and you can never see the error code, which would help you figure out what's going on. Fortunately there's an easy fix (see "Stop the BSOD Reboots").