How to troubleshoot PC startup problems – Windows XP, Windows Vista and Windows 7
The following is a list of the most common situations that were found to be the causes of startup problems when a computer running any version of Windows won’t start up, or starts up properly randomly after the user has gone through a routine that involves using the reset button, switching off the on/off switch on the power supply, smacking the case, etc.
1. A loose screw in the case was found to have been rolling around in the case. If it came to rest so that it was shorting the motherboard, the computer would fail to boot. If it came to rest where it wasn’t shorting anything, the computer would boot properly. Hence the random startups.
2. – The power supply was failing. Installing a new power supply unit solved the problem.
3. – There were some blown of faulty capacitors on the motherboard that were found to be bloated and/or leaking. The capacitors are the tin-can shaped components that stick up from the surface of the motherboard. Bloated and blown capacitors are usually caused by cheap power supplies (PSUs), or by a faulty manufacturing process. A few years ago, there was a spate of faulty capacitors used in motherboards when materials of poor quality was used in their manufacture. The capacitors store an electrical charge and are used to stabilise the power supply to the motherboard. Faulty or blown capacitors can cause RAM memory corruption and system lockups. Replacing the motherboard and/or the power supply fixed the problem.
Click here! to go to information on power supplies on this website.
Note that Windows XP, Windows Vista and Windows 7 will almost certainly have to be reactivated over the telephone to Microsoft if the computer’s motherboard is replaced. Read the Windows Product Activation page on this site for more information on WPA.
4. – The fan of the processor’s cooling unit was working intermittently. On the occasions when the fan wasn’t working at startup, the temperature of the processor rose very quickly to the point where the overheating protection circuitry built into the motherboard would switch the computer off. If the faulty fan was working at startup, the computer would start up properly. Replacing the cooling unit fixed the problem.
5. – The hard disk drive was found to be failing. It was locking up while the operating system was loading. The computer could be started up with the Windows CD, because only the RAM memory was involved in the boot process. But when any attempt was made to repair Windows, errors made by the failing hard drive usually resulted in the attempt having to be aborted. Replacing the hard drive and restoring a master image or backup of the system fixed the problem.
You can use the hard-drive testing utility that Windows provides called chkdsk in Windows XP, Windows Vista and Windows 7/8.1/10, but most of the hard-disk-drive manufacturers (Seagate, Toshiba, Western Digital, etc.) provide a better diagnostic utility that can be used to diagnose problems with their drives from their websites. These utilities might also be able to partition and format a hard disk drive.
Note well that if such a utility is used on a faulty system (suffering from faulty RAM, an inadequate power supply unit, a faulty motherboard, etc.) it could produce unreliable results.
6. – Faulty RAM memory can be the cause of similar lockup problems, making Windows produce all kinds of error messages that usually point everywhere except to faulty RAM. If there are two memory DIMM modules fitted to the motherboard, try using only one of them at a time in order to determine if only one of them is faulty. To do that involves opening the case and removing one of the DIMM modules. Consult the motherboard’s manual to make sure that you are installing the only module in the correct DIMM slot. Some motherboards allow any slot to be used, but others require a single module to be installed in the first slot. The illustrated manual will provide you with the required information. If you don’t have a manual, a copy should be available as a download from its manufacturer’s website.
You can run software diagnostic tests on the RAM by using Memtest from http://www.memtest86.com/ or by using Microsoft’s Memory Diagnostic tool from:
7. – The video/graphics card was found to be loose in its socket or not all the way in the socket. As a result the computer starts up but there is no display on the monitor. Removing the video/graphics card and seating it properly in its slot fixed the problem. Note that sometimes if the video card is screwed in too tightly to its slot, the end can be raised out of the slot.
8. – The BIOS settings enabled for the processor were found to be incorrect, or the BIOS settings for the processor’s clock multiplier or the Front Side Bus (FSB) overclocked the motherboard to a level that prevented it from allowing the computer to boot. Entering the BIOS at at startup and enabling the fail-safe or default settings options usually fixes the problem. Visit the BIOS section on this site for more information on the standard BIOS used by WinXP, which cannot use the new UEFI BIOS that Windows 8.0/8.1/10 uses.
The first action to take to solve a startup problem is to open the PC’s case. You should do that on a clear desk with the computer switched off but still connected to the mains outlet, which is also switched off. Under those conditions the computer is earthed. Before touching any of the components earth yourself by touching the case. Remove the RAM modules and adapter cards. If the gold contacts are oxidised and therefore look dull, use a pencil eraser to clean them.
Note that you have to be careful not to rub too hard or you may remove the metal of the contacts as well. Clean the contacts gently or make use of a cleaning solution that you can purchase from electronics stores.
You can use kontak cleaner as the search query in a search engine to find the best cleaning solution.
It’s also a good idea to buy a can of compressed air from a computer store that is used to blow dust out of the processor and case fans and out of the power supply. A vacuum cleaner should not be used because of the danger of static electricity, which can be fatal to electronic components.
If you can’t find out the cause of the problem yourself from the information provided above, the best course of action would be to take the computer’s base unit to a computer repair shop that has a good reputation. Take care never to allow cowboy operators anywhere near your computer, because you could pay one a small fortune and still wind up with a faulty PC.