正面回答者有分 ！

[HKer_007]

各位ggjj:

请问为什么我在winXP下用VC6.0编程中
调用ExitWindowsEx(EWX_SHUTDOWN)函数不起作用?

[thd111]

必须先取得关机的权限

[yhb4]

要有关机权限

[HKer_007]

怎样取得？

[xuying]

要有关机权限才可以关机。最好用InitiateSystemShutdown()函数。
HANDLE hToken; // handle to process token
TOKEN_PRIVILEGES tkp; // pointer to token structure

BOOL fResult; // system shutdown flag

// Get the current process token handle so we can get shutdown
// privilege.

if (!OpenProcessToken(GetCurrentProcess(),
TOKEN_ADJUST_PRIVILEGES | TOKEN_QUERY, &hToken))
ErrorHandler("OpenProcessToken failed.");

// Get the LUID for shutdown privilege.

LookupPrivilegeValue(NULL, SE_SHUTDOWN_NAME,
&tkp.Privileges[0].Luid);

tkp.PrivilegeCount = 1; // one privilege to set
tkp.Privileges[0].Attributes = SE_PRIVILEGE_ENABLED;

// Get shutdown privilege for this process.

AdjustTokenPrivileges(hToken, FALSE, &tkp, 0,
(PTOKEN_PRIVILEGES) NULL, 0);

// Cannot test the return value of AdjustTokenPrivileges.

if (GetLastError() != ERROR_SUCCESS)
ErrorHandler("AdjustTokenPrivileges enable failed.");

// Display the shutdown dialog box and start the time-out countdown.

fResult = InitiateSystemShutdown(
NULL, // shut down local computer
"Click on the main window and press \
the Escape key to cancel shutdown.", // message to user
20, // time-out period
FALSE, // ask user to close apps
TRUE); // reboot after shutdown

if (!fResult)
{
ErrorHandler("InitiateSystemShutdown failed.");
}

// Disable shutdown privilege.

tkp.Privileges[0].Attributes = 0;
AdjustTokenPrivileges(hToken, FALSE, &tkp, 0,
(PTOKEN_PRIVILEGES) NULL, 0);

if (GetLastError() != ERROR_SUCCESS)
{
ErrorHandler("AdjustTokenPrivileges disable failed.");
}

[dy_paradise]

同意楼上