Linux and win7 dual system time error problem

The system was just installed with centos 5.4 and win7. Found that the win7 system time is wrong, the machine does not go online, every day when booting, it will always be 8 hours slow, I don't know how it happened, because I am busy with other things, so after a few days, I found the reason, and later found that the windows time service is not automatic. So take it for granted that this is the reason.

After using it a few times, I didn't find any abnormality. Because I didn't plug in the network cable when I booted up, I went straight to ubuntu and found that the time was 8 hours. The Internet cable was normal, so I felt that it was not normal, so I felt that it was not normal. Restarted into win7 and found that it was slow for 8 hours, only to realize that this may be caused by different system settings. So google:

two concepts:

UTC is Universal Time Coordinated, Coordinated Universal Time

GMT is Greenwich Mean Time, Greenwich Mean Time

Windows
The way to look at system hardware time by default with Mac/Linux is different:

Windows treats system hardware time as local time, ie operating system
is the same as the time displayed in the BIOS.

Linux/Unix/Mac regards hardware time as UTC. The time displayed in the operating system is converted from hardware time. For example, when Beijing time is GMT+8, the time displayed in the system is hardware time. +8.

This way, when there are multiple systems coexisting in the PC, there is a problem.

If your Linux setting time zone is Beijing East 8th District, the current system time is 9:00AM. At this time, the actual stored in the hardware is UTC time 1:00AM. At this time, after you reboot into Windows, you will find that the time displayed in the windows system is 1:00AM, which is eight hours slower than Linux. Similarly, if you change the system time in Windows or synchronize the system time with the network, and then go to Linux, the system will be faster for 8 hours. In areas where daylight saving time is implemented, the situation may be more complicated.

The solution to this problem:

1. Allow Ubuntu to use UTC time consistent with Windows.

Ubuntu defaults to UTC, which coordinates World Time, and win7 uses this timing method. This will result in a difference between Windows and Ubuntu time calculations.

You can use the following method to get Consistent time:

sudo gedit /etc/default/rcS

Find this line: UTC=yes

Change yes to no

in fedora (I am fedora 13), open System–>Administration–>Date & Time to remove the checkmark in front of System clock uses UTC under the Time Zone tab. The system time is normal after a few minutes.

2. Modify the way Windows treats hardware time so that it can be set on Ubuntu only after it has been modified on Windows.

Let Windows use hardware time as UTC

start->run->cmd, open the command line program (Vista must open the command line program as an administrator to have permission) Access the registry), enter the following command on the command line and press Enter

Code:

Reg add HKLM\\SYSTEM\\CurrentControlSet\\Control\\TimeZoneInformation /v RealTimeIsUniversal /t REG_DWORD /d 1 < Br>