The Pc is randomly auto restart without prompting any messages.I scan all the files but no virus found.I had tried format the PC and at first it work properly but after a period,this problem occur again.. I feel very frustrated especially when i didn't save my work then it suddenly restart.when it restart,sometimes when it get into the logon screen it will restart again.it didn't give any warning and no error recorded in the event viewer.. Anyone have idea on this?is this problem cause by worm or hardware problem like motherboard? Please kindly reply if you experience this before.Thank you.

The biggest cause of random reboots is overheating. Ensure all fan's are working and the case is clean (inside) and also ensure free airflow around the case.

Thanks your reply.I am sure the fan is working and the environment here is cool. And everytime i boot the PC,when it go to the logon screen,it will restart again... Do you have any idea about these?Thanks

Check the system event log and look for record 1001 (ie sysdump). If you get sysdump record, your windows was crashed and auto restart. Zoom in the sysdump record, drop down the bugcheck code and search goggle to find the possible cause of your problem. You can use windbg to format minidump (c:\windows\minidump\*.dmp) If you cannot find the sysdump event log, it is hardware problem. I don't think it is overheat, as most CPU and mother board power off the system to cool down the temperature within the comouter case. Restart the system for overheat problem will put the PC at recursive reboot which does not make sense. The auto restart may be related faulty ram, low power supply, the faulty capacitor of the motherborad.

Thanks your comment,Cheng.There are record 1001 in the event viewer but it happen one time only.I mean sometimes even when i start the PC,and it reboot itself 2-3 times,there are no record 1001 written in the event log.So,my PC's problem is caused by motherboard's problem?

Hi Alice, The auto-reboot problem is a hardware problem as there has no system event log which implies this an unschedule re-start. Most probably this is power supply unit problem at within the computer case. How much does it cost to buy a PSU which has a bigger capacity thqn the PSU of your PC? If it is cheap, it is worthwhile to replace your PSU. Question 1. Can simulate the auto-reboot problem? For example you connect a USB device to your PC or whenever you a game and your W2K restart. This will definietely useful to diagnostic the root cause of your problem. 2. What is your PC configuration? The manufacturere of the CPU. motherboard, display card, PSU, hard disk and windows version and patch level. 3. What is the bugcheck code of system event log 1001? When did it occur?

Cheng, The auto-reboot is happen randomly.But at least 1 time per day.At first is when i start up the PC,when it started getting into the window,i mean may be the logon window screen is show..then it reboot again.This can happen 2-3 times during startup the PC. OK,then when the PC is startup successfully, and i doing my work,it will be auto reset without prompting any message and usually it will happen around 4pm-5pm but sometimes it can be happen at 1pm or even sometimes didn't happen. The work that i doing that time just normal like surf the net,open some file to read.And i have scan my PC,there are no virus found. my Pc configuration is as below:- Computer: x86 Family 6 Model 8 Stepping 6 AT/AT COMPATIBLE 130,544 KB RAM System: Microsoft Windows 2000 Service Pack 4 Computer: ACPI Uniprocessor PC Display adapters: ATI Technologies Inc.RAGE 128 VR AGP Disk drives: Maxtor 6Y080P0 IDE ATA/ATAPI controllers Network adapters: 3Com EtherLink XL 10/100 PCI For Complete PC Management NIC(3C905C-TX) The Save dump is happen as soon as i start up my PC,the description is as below: "The computer has rebooted from a bugcheck. The bugcheck was: 0xc0000218 (0xe12c8a28, 0x00000000, 0x00000000, 0x00000000). Microsoft Windows 2000 [v15.2195]. A dump was saved in: C:\WINNT\Minidump\Mini101204-01.dmp." Is the information i stated here is enough to find out what problem with my PC?and thanks a lot for your help:)