Troubleshoot boot-up and shutdown problems
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By Lincoln Spector, PC World
Does your PC hang, complain, or flat-out blue-screen when you start it up or shut it down? You start your workday by booting up your Windows PC. You end the day by shutting it down again. A problem at boot time can keep you from your work -- or your fun. And a shutdown issue takes a lot of the fun out of getting up and leaving your PC.
Why does my PC reboot when I tell it to shut down?
When something causes a system failure at shutdown, Windows responds by rebooting.
Fortunately, you can turn off that behavior. Select Start Run (just Start in Vista/Win7), type sysdm.cpl, and press Enter. Click the Advanced tab, and then click the Settings button under "Startup and Recovery" (as opposed to the other two Settings buttons on that tab). Uncheck Automatically restart.
That will stop the reboots, but it won't fix the underlying problem: the system failure causing them. Still, it might give you an error message that you can research to find a solution.
Today, the problem is more likely to be caused by a hardware or driver issue. If the problem started soon after you added a new peripheral or updated an old driver, try removing the recent addition. Check vendors' Web sites for updated drivers for your new hardware, or use Windows' Device Manager to roll back to older ones if you suspect an update has caused the trouble.
Why does my PC occasionally freeze at Windows' boot-up screen?
First, you need to figure out if this a Windows problem or a hardware problem. Try to notice at what point the computer hangs (admittedly difficult if the problem doesn't happen regularly). If Windows starts loading before disaster strikes, that means there's an issue with a startup file or a Windows component, and you can skip the next five paragraphs. If everything freezes before the PC starts loading Windows from the hard drive, the cause definitely lies somewhere in the hardware.
If you're unsure where the problem is, try to isolate it by booting from a CD, DVD or flash drive. Again, the intermittent nature of your problem makes the task difficult; you may have to do this daily for a while before you can be confident that the problem is on the hard drive -- either a Windows glitch or something with the hard drive itself.
If your PC tries to boot from the CD/DVD drive before the hard drive (as most do), a defect in that drive may interfere with the boot even when the drive is empty. This could also be the case with USB ports and floppy drives.
To determine which drive could be the cause, go into your system setup program and change the boot order. To do this exactly, look for a message soon after the PC boots that says something like "Press F2 for Setup", since it varies from BIOS to BIOS. Once in the setup program, search the menus for something like "Boot Options" or "Boot Order". Make your hard drive the first device in the boot order, and then save and exit. If that fixes the problem, experiment with putting different devices before the hard drive, one at a time, until the problem returns.
If all of the above tests point to a hard-drive problem, its recommended to error-check and defrag the hard drive. You'll find the tools for both jobs by right-clicking the C: drive in Windows Explorer and selecting Properties, Tools. When you click Check Now under "Error-checking", make sure that Automatically fix file system errors is checked before you click Start. If Windows reports that it can't perform the check because the disk is in use, select Yes (in XP) or Schedule disk check (in Vista/Win7) for the check to run at the next boot.
If that doesn't help, and the PC freezes before the Windows logo appears, open the computer's case (if it's a desktop) and check the cables connecting the hard drive to the motherboard and the power supply. You might even consider replacing them. If you have a laptop, bring it to us and have a professional look at it.
If Windows comes up and then freezes, something is wrong with your boot or autoloading sequence. The Event Viewer may tell you what. Select Start Run, type eventvwr, and press Enter. In the left pane, select System. In the right (XP) or center (Vista/Win7) pane, find and double-click an event with a red flag and the word Error. If the resulting dialog box doesn't provide useful information, click the URL in the description box (XP) or click the Event Log Online Help link (Vista/Win7).
Finally, you might try fiddling with your autoloading programs. Windows launches them all at once, and that can cause conflicts. You might also consider disabling some autoloaders.