A system hang is something that troubles operators quite a bit. When a hang occurs, the symptoms are usually a “blue screen,” failure to start the system, the display “freezing” with no response, no input from the mouse or keyboard, abnormal interruption while software is running, etc. Although there are many causes of hangs, they always come down to two aspects: hardware and software. Hangs caused by hardware 【Poor heat dissipation】 The monitor, power supply, and CPU all generate a lot of heat while working, so maintaining good ventilation is very important. If the monitor overheats, it can cause color and image distortion and even shorten the monitor’s life. Working too long can also make heat dissipation of the power supply or monitor poor and cause the computer to hang. CPU heat dissipation is an important issue related to the stability of computer operation, and it is also a “hard-hit area” for cooling failures. 【Improper movement】 Strong vibration while moving the computer often loosens internal components, causing poor contact and resulting in system hangs, so violent vibration should be avoided when moving a computer. 【Dust killer】 Too much dust inside the machine can also cause hang failures. For example, if too much dust sticks to the floppy drive head or the CD-ROM laser head, it will cause read/write errors, and in serious cases it may cause the computer to hang. 【Device mismatch】 For example, if the motherboard’s main frequency and the CPU’s main frequency do not match, or if an old motherboard is overclocked with the external frequency set too high, stable operation may not be guaranteed, thus leading to frequent hangs. 【Software/hardware incompatibility】 3D software and some special software may fail to start normally or even fail to install on certain PCs, and there may be software/hardware compatibility problems involved. 【Memory module failure】 This is mainly caused by a loose memory module, poor soldering, or the quality of the memory chips themselves. Memory contact faults should be ruled out according to the specific situation. If there is a quality problem with the memory module itself, then the only solution is to replace the memory. 【Hard disk failure】 This is mainly due to hard disk aging or bad tracks and bad sectors caused by improper use. In that case, the machine is very prone to hanging during operation. Specialized tool software can be used for troubleshooting; if the damage is serious, the only option is to replace the hard disk. In addition, for motherboards that do not support UDMA 66/100, attention should be paid to the hard disk operating mode setting in CMOS. 【CPU overclocking】 Overclocking raises the CPU’s working frequency, but at the same time it may also make performance unstable. The reason is that the CPU’s speed in accessing data in memory is already faster than the speed at which memory exchanges data with the hard disk. Overclocking makes this contradiction even more prominent, increasing the chance that required data cannot be found in memory or virtual memory, and then “exception errors” appear. The solution is of course simple: return the CPU to its normal frequency. 【Hardware resource conflicts】 This is caused by setting conflicts involving the sound card or display card, leading to exception errors. In addition, if there are conflicts in interrupts, DMA, or ports of other devices, a few drivers may produce exceptions, leading to hangs. The solution is to start in “Safe Mode” and make appropriate adjustments in “Control Panel” → “System” → “Device Manager.” For exception errors caused by drivers, the registry can be modified. Select “Run,” type “REGEDIT,” enter the Registry Editor, use the “Find” function in the menu, find and delete all “primary keys” and “key values” related to the driver prefix string, and restart. 【Insufficient memory capacity】 The more memory the better; it should not be less than 0.5% to 1% of hard disk capacity. If this problem appears, replace it with a memory module as large as possible. 【Inferior components】 A few dishonest dealers, when assembling compatible PCs for customers, use low-quality boards and memory, and some even sell counterfeit motherboards and remarked CPUs and memory. Such machines are very unstable in operation, and hangs are unavoidable. Therefore, users should stay alert when buying a computer, and can use some newer tool software to test the PC, run long continuous stress tests (such as 72 hours), and try to get the longest possible warranty period. Hangs caused by software 【Virus infection】 Viruses can sharply reduce computer efficiency and cause frequent hangs. At this time, use antivirus software such as KV300, Kingsoft Antivirus, Rising, etc. to carry out a full virus scan and removal, and be sure to upgrade the antivirus software regularly. 【Improper CMOS settings】 This fault is very common. For example, improper hard disk parameter settings, mode settings, or memory parameter settings may make the computer unable to start. If memory without ECC capability is set as having ECC capability, memory errors will cause hangs. 【Accidental deletion of system files】 Since Windows 9x startup requires files such as Command.com, Io.sys, Msdos.sys, if these files are damaged or accidentally deleted, then even if all hardware settings in CMOS are correct, it will still be useless. Solution: start the computer with a boot disk from the same version of the operating system, then type “SYS C：” to transfer the system files again. 【Initialization files damaged】 Since Windows 9x startup needs to read System.ini, Win.ini, and the registry files, and if Config.sys and Autoexec.bat exist, these two files will also be read. As long as there is incorrect information in these files, hangs may occur, especially in these four files: System.ini, Win.ini, User.dat, and System.dat. 【Dynamic-link library files (DLL) missing】 There is another kind of file in the Windows operating system that is also very important: dynamic-link library files with the extension DLL. By nature these are shared files, that is, one DLL file may be called by multiple software programs while running. If we delete an application, its uninstaller may record the files it installed and prepare to delete them one by one. At that time, a dynamic-link library file may be deleted even though it is still being used by other software. If the missing DLL is an important core library file, then the system will hang, or even crash. We can use tool software such as “Super Bunny” to delete useless DLL files, which will avoid mistaken deletion. 【Too little free hard disk space or too many fragments】 If there is too little free space on the hard disk, some applications require a large amount of memory to run, so virtual memory is needed, and virtual memory is provided by the hard disk. Therefore, the hard disk must have enough free space to meet the needs of virtual memory. At the same time, users should develop the good habit of regularly organizing the hard disk and clearing junk files from it. 【BIOS upgrade failure】 A BIOS backup should be made just in case, but if your system needs a BIOS upgrade, then before upgrading you had better make sure that the BIOS version you are using matches your PC. If the BIOS upgrade is incorrect or an unexpected power failure occurs during the upgrade, your system may fail to boot. So before upgrading the BIOS, be sure to find out the BIOS model clearly. If the BIOS upgrade tool you use can back up the current BIOS, then copy the old BIOS onto a disk. Also check whether the system supports BIOS recovery, and you should also know how to restore it. 【Improper software upgrading】 Most people may think software upgrading will not cause problems, but in fact, some shared components are also upgraded during the process, and other programs may not support the upgraded components, causing various problems. 【Abuse of beta software】 It is best to use beta software as little as possible, because test software usually has some BUGs or is not stable enough in some respects. After use, it may cause program errors involving data loss, hangs, or the system being unable to boot. 【Illegal software uninstalling】 Do not directly delete the directory where the software is installed. If you delete it directly, a lot of junk will remain in the registry and the Windows directory; over time the system will become unstable and cause hangs. 【Use of pirated software】 Such software may hide viruses. Once executed, they may automatically modify your system and cause hangs during operation. 【Defects in application software】 This situation is common, for example running 16-bit applications under Win 98 that worked well under DOS or Windows 3．1. Win 98 is 32-bit; although it claims compatibility, in many places it cannot coordinate with 16-bit applications. There are also cases where peripheral drivers that worked normally under Win 95 may have problems after the operating system is upgraded, causing the system to hang or fail to start normally. In such cases, a newer version of the peripheral driver should be found. 【Too many programs started】 This exhausts system resources, so the data needed by some programs cannot be found in memory or virtual memory, and exception errors may also occur. 【Illegal operations】 Improperly opening or releasing related programs with illegal formats or illegal parameters may also cause the computer to hang. Please be sure to remember the correct formats and related parameters, and do not open or release unfamiliar programs casually. 【Abnormal computer shutdown】 Do not directly use the power button on the case, otherwise it may damage or lose system files, causing hangs during auto-startup or operation. For systems such as Windows 98/2000/NT, this is especially important; in serious cases, it can cause system collapse. 【Conflicts in memory】 Sometimes all kinds of software run normally, yet suddenly the system hangs for no apparent reason; after restarting, those applications run normally again. This is a false hang. The reason is mostly memory resource conflicts in Win 98. As everyone knows, application software runs in memory, and after an application is closed, memory space can be released. But due to design reasons, some applications cannot completely release memory even after being closed. When the next software needs to use that same memory address, a conflict occurs.
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