POST stands for Power On Self Test. It is the routine the BIOS runs immediately after the computer powers on and before the computer displays the screen with the company logo or BIOS information on it. If there is a serious problem with the computer's hardware, the POST can hang or produce error tones preventing your computer from booting. These are the steps you can use to diagnose your problem.
NOTE: If your computer's fans do not spin when you press the power button, your computer is not powering on. This guide does not address that issue, yet I hope to have another guide for it soon.
NOTE: To prevent damage to your computer, do not touch, remove or install hardware while the computer is plugged in and do not work in the inside of your computer while standing on carpet flooring. This can cause static electricity buildup to damage boards.
Sometimes you may get beep codes when you try to start the computer. This website has a few of the common ones depending on your BIOS.
BIOS beep codes
One common and easily fixed cause of no POST is loose RAM. With your computer unplugged, take your RAM out and put it back in. This will ensure that the RAM is secure in its brackets. See if your computer will boot now.
If your computer will not boot, it is time to start the process of elimination. The point is to eliminate each piece of hardware as the problem. The easiest thing to test is removing optical and hard drives. If this does not fix the problem, try removing pci/agp cards. If removing any of these devices causes your computer to post, you should narrow down the specific device by re-connecting devices one after another. When you find the offending device, make sure it is not data or power cables causing the problem.
At this point, if your computer does not boot, you should be down to the power supply, motherboard, processor and RAM as possible causes. You should replace the power supply and RAM with known good devices to test them. If replacing RAM helps, make sure that it was bad RAM that was the problem and not a bad RAM slot. If at this point, your computer still will not boot, it must be your motherboard and/or processor (probably processor). At this point, I would replace both, because even if you find out one is causing the problem, it might be the other that damaged it.
Tuesday, November 11, 2008
Saturday, November 8, 2008
What you can do with your Windows XP cd other than install Windows
This article is to explain the recovery console and repair install functions on the Windows XP/2000 disks. Windows Vista lacks these features.
The very first step is to get your computer to boot off of the disk. The easiest way is to bring up a one-time boot menu. This is usually achieved by pressing "esc", "F10" or "F12" keys while the computer is starting. Every motherboard is different, so there is no guarantee that will work. The second method is to enter the bios settings. Pressing the "esc", "F1", "F2", or "del" keys while the computer is starting should get you in. Hopefully, your bios splash screen will tell you what button to press to get into either you're one-time boot menu or your bios settings.
If you get into your one-time boot menu, simply select the optical drive your Windows disk is in, and then press enter when it says "press any key to boot from cd". If you get into your BIOS, you need to locate your boot device order menu. This will list your possible boot medium and what order in which the computer will try to boot from. Just get your optical drive to the top of the list. You may also have to change which optical drive it tries if you have two of them. Since there are many different motherboards with different BIOS, you may have to use google.com to get yours set up the way you need.
First I will explain the recovery console. After you boot from the Windows XP disk, you will eventually get to a screen with three options. One of them will be "press r to boot into the recovery console". Press 'r' and then log into your windows installation. This should be self explanatory. When you are done logging on, you will be greeted with a command prompt c:/
The main reason people usually come to a command prompt is to run a file-system check if their computer will not boot Windows. To do this, enter "chkdsk c: /r" and press enter (unless I specify otherwise, never include the quotes). This command will check the c: and repair any errors it can. It will also tell you how many bad sectors there are when they are finished. You should ask someone knowledgeable about the subject if you should replace your hard drive according to how many bad sectors came up.
You can also run other DOS commands from the recovery console including moving, copying and deleting files. This can be useful in virus removal. Consult a DOS command guide for more details.
If your chkdsk did not get your computer booting windows, you can try a repair install. This will replace the Windows system files with new ones, hopefully fixing your problem and not losing your personal data and programs. Keep in mind, this process is not perfect. You should back up any important data before starting it.
After booting from the Windows XP and getting to the first blue screen with three options, press enter. After that, you should be greeted with the EULA (end user license agreement). Press F8 to accept. At this point, setup should list your operating system and ask you if you want to repair it. Press 'r' and it will start the process.
If setup takes you to a list of your hard drives and partitions, exit setup immediately, as going further will destroy your information. There are 2 reasons that setup will skip the repair install screen:
1) Setup could not detect your OS. If this is the case, you must wipe/reload windows to fix it.
2) You put in the wrong disk. If you have Windows XP Professional, you can only repair install with the Windows XP Professional disk. Windows XP Media Center will not work.
After running the repair install, your operating system may boot and it may not. If it does not, you should start considering a wipe/reload of Windows on your computer.
The very first step is to get your computer to boot off of the disk. The easiest way is to bring up a one-time boot menu. This is usually achieved by pressing "esc", "F10" or "F12" keys while the computer is starting. Every motherboard is different, so there is no guarantee that will work. The second method is to enter the bios settings. Pressing the "esc", "F1", "F2", or "del" keys while the computer is starting should get you in. Hopefully, your bios splash screen will tell you what button to press to get into either you're one-time boot menu or your bios settings.
If you get into your one-time boot menu, simply select the optical drive your Windows disk is in, and then press enter when it says "press any key to boot from cd". If you get into your BIOS, you need to locate your boot device order menu. This will list your possible boot medium and what order in which the computer will try to boot from. Just get your optical drive to the top of the list. You may also have to change which optical drive it tries if you have two of them. Since there are many different motherboards with different BIOS, you may have to use google.com to get yours set up the way you need.
First I will explain the recovery console. After you boot from the Windows XP disk, you will eventually get to a screen with three options. One of them will be "press r to boot into the recovery console". Press 'r' and then log into your windows installation. This should be self explanatory. When you are done logging on, you will be greeted with a command prompt c:/
The main reason people usually come to a command prompt is to run a file-system check if their computer will not boot Windows. To do this, enter "chkdsk c: /r" and press enter (unless I specify otherwise, never include the quotes). This command will check the c: and repair any errors it can. It will also tell you how many bad sectors there are when they are finished. You should ask someone knowledgeable about the subject if you should replace your hard drive according to how many bad sectors came up.
You can also run other DOS commands from the recovery console including moving, copying and deleting files. This can be useful in virus removal. Consult a DOS command guide for more details.
If your chkdsk did not get your computer booting windows, you can try a repair install. This will replace the Windows system files with new ones, hopefully fixing your problem and not losing your personal data and programs. Keep in mind, this process is not perfect. You should back up any important data before starting it.
After booting from the Windows XP and getting to the first blue screen with three options, press enter. After that, you should be greeted with the EULA (end user license agreement). Press F8 to accept. At this point, setup should list your operating system and ask you if you want to repair it. Press 'r' and it will start the process.
If setup takes you to a list of your hard drives and partitions, exit setup immediately, as going further will destroy your information. There are 2 reasons that setup will skip the repair install screen:
1) Setup could not detect your OS. If this is the case, you must wipe/reload windows to fix it.
2) You put in the wrong disk. If you have Windows XP Professional, you can only repair install with the Windows XP Professional disk. Windows XP Media Center will not work.
After running the repair install, your operating system may boot and it may not. If it does not, you should start considering a wipe/reload of Windows on your computer.
Wednesday, October 22, 2008
How to remove malware from your computer.
Some of my friends are having malware problems. I think it may be easiest to post the process I use at work. This will clean the computer most of the time. One thing I need to say is that removing malware may cause data loss and/or your operating system to become unusable. However, leaving the malware on your computer is unacceptable for most people.
First thing I will note is the definition of malware, so you have an idea what you are dealing with.
Virus malware effects your computer as a whole and includes:
viruses - malware that propagates (infects) only with user intervention.
worms - malware that propagates (infects) without user intervention.
rootkits - malware that uses Windows rootkit technology to infect computers. Very dangerous.
Spyware malware attaches itself to your browser and includes:
Spyware - malware which either lifts your keystrokes or records your activity.
Adware - displays pop-ups, re-directs webpages, and changes ads on webpages.
Greyware - programs that are not intentionally malicious, but is generally not considered good to have on your computer either because of performance or instability.
Now just listing a step by step process would not be practical since each infection is different and there are many different ways to remove malware. Instead, I will give you guidelines and leave the specifics to you. You may have to google certain processes, since I don't want to use up too much space explaining details. Also, all links for programs are at the bottom.
* If a virus scan detects viruses in the restore, turn it off. It means all your restore points are gone, but that is the only way to get rid of viruses there.
* Use online scanners unless you have a good virus scanner installed (ie: NOD32, bitdefender, or kaspersky). The virus scans should be ran first thing in the removal process so you can get an idea what you are up against, and to get rid of the easy malware. If it detects restore viruses, turn restore off. Virus scans should also be run at the end of the virus removal process, to pick up any malware the other malware removers didn't remove.
* Use hijack-this early on to remove registry keys and other values to help remove the malware later. A guide to using HijackThis I've included with the link to the program. I would recommend removing any program from startup that isn't necessary or wanted, as this will also help speed up you computer later.
* Run CCleaners file remover and registry cleaner. Not only will this help speed up future scans, but it may take out some malware in temporary files.
* ComboFix and SDfix: These programs remove some of the more nastier rootkits and viruses. It should be run if anything serious is on your computer. They should be ran after using Hijack-this and CCleaner. Download Combofix to your desktop and rename it something like deleteStuff.exe. Download SDfix, extract it, and then run "runthis.bat" and press u to update. Afterwards it will extract itself again. then run combofix and SDfix (runthis.bat) in safemode.
After running an online scan, hi-jackthis, ccleaner, combofix and sdfix, most of the malware should be gone. Install ad-aware and spybot S&D to start removing spyware. In the "tools" section of spybot, you will see the activeX and BHO's section. You should remove all of them (you can re-install anything you remove later). After than, run the basic scans.
If you see a BHO that keeps popping up again after deletion, or any other file that seems like it just won't go away, you will have to boot the recovery console using the windows cd and remove it there. Use the command del [file path]. Example: del c:\windows\system32\badBHO.bat.
Keep running anti-spyware and anti-virus scans until they all come up clean. If anything won't go away after the first scan, then you will need to remove them manually as the last paragraph explained. Afterwards, if your computer does not run well (viruses can damage your OS) try a repair install. If that doesn't help, you may end up having to wipe/reload windows anyway.
links:
Eset - has an online virus scanner
Bitdefender's online scanner - another online virus scanner
Kaspersy - has a online virus scanner based on java (ie: doesn't need IE)
HijackThis
CCleaner
Combofix guide & DL - sometimes their DL link does not work
SDfix
Safer Networking - home of spybot S&D
lavasoft - creators of adaware
edit: apparently blogger.com does not want to post a href to the hijackthis tutorial. Here it is http://forums.majorgeeks.com/showthread.php?t="38752"
First thing I will note is the definition of malware, so you have an idea what you are dealing with.
Virus malware effects your computer as a whole and includes:
viruses - malware that propagates (infects) only with user intervention.
worms - malware that propagates (infects) without user intervention.
rootkits - malware that uses Windows rootkit technology to infect computers. Very dangerous.
Spyware malware attaches itself to your browser and includes:
Spyware - malware which either lifts your keystrokes or records your activity.
Adware - displays pop-ups, re-directs webpages, and changes ads on webpages.
Greyware - programs that are not intentionally malicious, but is generally not considered good to have on your computer either because of performance or instability.
Now just listing a step by step process would not be practical since each infection is different and there are many different ways to remove malware. Instead, I will give you guidelines and leave the specifics to you. You may have to google certain processes, since I don't want to use up too much space explaining details. Also, all links for programs are at the bottom.
* If a virus scan detects viruses in the restore, turn it off. It means all your restore points are gone, but that is the only way to get rid of viruses there.
* Use online scanners unless you have a good virus scanner installed (ie: NOD32, bitdefender, or kaspersky). The virus scans should be ran first thing in the removal process so you can get an idea what you are up against, and to get rid of the easy malware. If it detects restore viruses, turn restore off. Virus scans should also be run at the end of the virus removal process, to pick up any malware the other malware removers didn't remove.
* Use hijack-this early on to remove registry keys and other values to help remove the malware later. A guide to using HijackThis I've included with the link to the program. I would recommend removing any program from startup that isn't necessary or wanted, as this will also help speed up you computer later.
* Run CCleaners file remover and registry cleaner. Not only will this help speed up future scans, but it may take out some malware in temporary files.
* ComboFix and SDfix: These programs remove some of the more nastier rootkits and viruses. It should be run if anything serious is on your computer. They should be ran after using Hijack-this and CCleaner. Download Combofix to your desktop and rename it something like deleteStuff.exe. Download SDfix, extract it, and then run "runthis.bat" and press u to update. Afterwards it will extract itself again. then run combofix and SDfix (runthis.bat) in safemode.
After running an online scan, hi-jackthis, ccleaner, combofix and sdfix, most of the malware should be gone. Install ad-aware and spybot S&D to start removing spyware. In the "tools" section of spybot, you will see the activeX and BHO's section. You should remove all of them (you can re-install anything you remove later). After than, run the basic scans.
If you see a BHO that keeps popping up again after deletion, or any other file that seems like it just won't go away, you will have to boot the recovery console using the windows cd and remove it there. Use the command del [file path]. Example: del c:\windows\system32\badBHO.bat.
Keep running anti-spyware and anti-virus scans until they all come up clean. If anything won't go away after the first scan, then you will need to remove them manually as the last paragraph explained. Afterwards, if your computer does not run well (viruses can damage your OS) try a repair install. If that doesn't help, you may end up having to wipe/reload windows anyway.
links:
Eset - has an online virus scanner
Bitdefender's online scanner - another online virus scanner
Kaspersy - has a online virus scanner based on java (ie: doesn't need IE)
HijackThis
CCleaner
Combofix guide & DL - sometimes their DL link does not work
SDfix
Safer Networking - home of spybot S&D
lavasoft - creators of adaware
edit: apparently blogger.com does not want to post a href to the hijackthis tutorial. Here it is http://forums.majorgeeks.com/showthread.php?t="38752"
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