|Component of Microsoft Windows
winver, short for Windows Version, is a utility included in most versions of Microsoft Windows used to obtain information about the operating system version. Depending on the Windows version, the tool is also referred to as Windows-version utility or Version Reporter Applet in its file version information on DOS-based Windows and Windows NT, respectively.
It was first introduced in Windows 3.0, where it was implemented as a simple message box with the Windows logo, major and minor version number, copyright notice and information about the currently active mode of operation. The tool also includes a custom MS-DOS executable stub that prints the version information onto the screen. It was kept virtually unchanged throughout the classic Windows series, with Windows 3.1 only changing the logo, and Windows 95 reducing the version information to the operating system name.
On NT-based Windows versions, the utility was included since Windows NT 3.1, where it was implemented similarly to its 16-bit counterpart as a simple box with the Windows logo, version and build numbers and a copyright notice. However, starting with Windows NT 3.5, it merely calls the
ShellAbout API function to display a standard about box, which aside from the version and copyright notices also contained information about the computer and the registered owner. With the introduction of the timebomb during the development of Windows 2000, winver was updated to query information about the timebomb, and if present, display it in the about box.
On Windows versions that don't include a standalone
winver.exe executable, such as Windows Server Core or the Windows Preinstallation Environment, the dialog can be invoked using the
rundll32 shell32,ShellAbout command. However, when invoked this way, the dialog won't include timebomb information, as that functionality is exclusive to the applet. The dialog caption will show garbled characters when invoked this way due to the differences between the arguments expected by
rundll32 and the actual signature of the function.[a]
rundll32expects the called function to have the signature of
void CALLBACK EntryPoint (HWND hWnd, HINSTANCE hInst, LPSTR lpszCmdLine, int nCmdShow). The garbled application name in the title bar (
MZor mojibake, depending on whether the -A or -W variant of the API is used) is a result of
ShellAbouttrying to parse the executable header of
shell32.dllas a zero-terminated string string. This is caused by a mismatch of the second parameter, where
ShellAboutexpects a pointer to a string while
rundll32provides the DLL's
HINSTANCE, which in Win32 is a pointer to the loaded module in memory.