以下提供两种方法获取Windows系统的开机时间

第一种是使用C++的函数，该方法使用当前时间减去系统运行时间，秒级的，偶尔存在1秒的差异

第二种是使用Windows的API，该方法获取到的时间与cmd命令systeminfo获取的时间是一致的，故推荐使用这种方法获取系统开机时间

1、C++

void GetSystemUpTime()
{
    DWORD iRunTime = GetTickCount();
    const int Num1 = 1000;
    const int Num2 = 1900;
    time_t nowTime;
    time(&nowTime);
    time_t systemUpTime = nowTime - (iRunTime / Num1);
    struct tm * timeInfo;
    timeInfo = localtime(&systemUpTime);
    printf("开机时间: %d-%d-%d %02d:%02d:%02d",timeInfo->tm_year + Num2,
            timeInfo->tm_mon + 1, timeInfo->tm_mday, timeInfo->tmhour, 
            timeInfo->tm_min, timeInfo->tm_sec);
}

2、

#include<stdio.h> 
#include<windows.h>  
#define NT_SUCCESS(x) ((x)>=0) 
const UINT SystemTimeInformation = 3;

typedef struct {   
    LARGE_INTEGER liKeBootTime;   
    LARGE_INTEGER liKeSystemTime;   
    LARGE_INTEGER liExpTimeZoneBias;   
    ULONG uCurrentTimeZoneId;   
    DWORD dwReserved; 
} SYSTEM_TIME_INFORMATION;   

typedef long (__stdcall *fnNtQuerySystemInformation)( 
        IN  UINT SystemInformationClass,    
        OUT PVOID SystemInformation,    
        IN  ULONG SystemInformationLength,  
OUT PULONG ReturnLength OPTIONAL); 

static fnNtQuerySystemInformation NtQuerySystemInformation = NULL;

int main(void) 
    {   
        NtQuerySystemInformation =   (fnNtQuerySystemInformation)GetProcAddress(LoadLibrary("ntdll.dll"), 
            "NtQuerySystemInformation");            
        if(NtQuerySystemInformation == NULL)    
        {       
            printf("Get NtQuerySystemInformation Addr Failed,err=%u\n",GetLastError());       
            return 0;   
        }   
        LONG status;    
        SYSTEM_TIME_INFORMATION sti;            
        status = NtQuerySystemInformation(SystemTimeInformation, &sti,sizeof(sti),0);    
        if(NO_ERROR != status)  
        {       
            printf("NtQuerySystemInformation Failed!n");        
            return 0;   
        }   
        FILETIME ft1,ft2;    
        SYSTEMTIME st;  
        memcpy_s(&ft1, sizeof(ft1),&sti.liKeBootTime,sizeof(sti.liKeBootTime)); 
        //将其转为文件时间  
        //将一个FILETIME结构转换成本地时间  
        if(0 == FileTimeToLocalFileTime(&ft1,&ft2))   
        {
            printf("FileTimeToLocalFileTime Failed err=%u\nn",GetLastError());        
            return 0; 
        } 
        //将文件时间转为系统时间
        if(0 == FileTimeToSystemTime(&ft2,&st))   
        {
            printf("FileTimeToSystemTimeFailed err=%u\nn",GetLastError());        
            return 0; 
        } 
        printf("Date: %02d-%02d-%04d Time: %02d:%02d:%02d ",st.wMonth,st.wDay,st.wYear, st.wHour,st.wMinute,st.wSecond);           
        getchar();  
        return 0; 
}

参考：

https://wwwblogs/fengbohello/p/4277082.html

https://blog.csdn/cxq_1993/article/details/48024193