There are many types of computer problems, and the system restarting automatically is one which is certainly annoying. It is most irritating if this happens while you are in the middle of some important work. It is even more frustrating if you have not saved your work.
There can be many reasons why your computer keeps shutting down. You first need to diagnose the exact cause of the problem and then carry out the computer repair accordingly.
There are higher chances for your system to be switched off due to the interference of a virus. The virus gets into the system and fiddles with crucial sections of the operating system, which may cause it to shut down automatically.
You need to install a good antivirus software and get the system scanned thoroughly for any malware and viruses. Also, see to it that the operating system and all hardware drivers are updated.
The power supply unit is an equipment that is installed in the cabinet to provide power to the system for operation. Your system may start rebooting if there is not enough power supplied to it for handling the programs running. If you are running intensive software, such as PC games, the system would require more power than what is actually available.
Another reason can be overheating of the power supply. After the power supply is used for a substantial period of time, there is a possibility of dust getting collected inside it. And this may cause it to overheat, resulting in switching off. If the power supply is at fault, you may need to get a new one installed.
As with the case of dust getting collected in the power supply, the motherboard and the processor can also collect dust, which may be the reason for their overheating. You need to open the cabinet and clean the dust off the parts.
The CPU board and the processor can also overheat because of many applications running. If this is the case, then it is suggested to keep the number of running applications as low as possible or increase the size of Random Access Memory (RAM). Bad capacitors on the motherboard is also one of the reasons.
The 'Automatically Restart' Setting
If you are using Windows XP operating system, there is a setting that indicates the system to reboot if it detects an error in the system's operation.
In order to check if this is the problem, click on 'Start' and 'Control Panel', then, select 'Performance and Maintenance'. Click on 'System', then the 'Advanced' option, and select 'Settings' from the 'Startup and Recovery' section. You will find an 'Automatically restart' option, which you need to be unchecked for preventing the system from rebooting.
You also need to check if the power cables are properly connected to the cabinet and to the UPS, as loose connections can also be a reason for system shutdown. The most common cause is due to overheating of the power supply and other internal parts.