Gflags Notes

General Information

To display the Gflags dialog box, at the command line, type Gflags (with no parameters).
To set flags in the registry or in kernel mode, you must be a member of the Administrators group on the computer. However, users with at least Guest account access can launch a program from the Gflags dialog box.
Gflags system-level registry settings appear in the registry immediately, but do not take effect until you restart the system.
Gflags image file registry settings appear in the registry immediately, but do not take effect until you restart the process.
The debugger and launch features in the Gflags dialog box are program specific. You can only set them on one image file at a time.
For information about kernel special pool, see the Windows Driver Development Kit (DDKs).
For information about debuggers and to obtain debuggers and documentation, see the Microsoft Windows 2000 Debugging Tools Kit, which is available from the Microsoft Windows Driver Development Kits (DDK) (http://go.microsoft.com/fwlink/?LinkId=1651) Web site.

Flag Details

To clear all flags, set the flag to -FFFFFFFF. Setting the flag to 0 adds 0 to the current flag value.
When you set the flags for an image file to 0xFFFFFFFF, Windows clears all flags and deletes the GlobalFlag entry in the image file subkey. The subkey is retained.

Dialog Box and Command Line

You can run Gflags by using its handy dialog box or from the command line. Most features are available in both forms, but the following features are only available from the dialog box:

Launch. Start a program using the specified flags.
Run the program in a debugger.
Kernel Special Pool Tag.

Registry Information

Debugging settings saved between sessions are stored in the registry. You can use the registry APIs, Regedit.exe, or Reg to query or change these values. The following table lists the types of settings and where they are stored in the registry.

Systemwide debugging values. ("Registry")	HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Session Manager\GlobalFlag
Program-specific debugging values. ("Image file")	HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\ImageFileName\GlobalFlag
Maximum stack trace capture size (maxdepth)	HKLM\System\CurrentControlSet\Control\Session Manager\MaxStackTraceDepth
Create user mode stack trace database (ust, 0x1000) for an image file	Windows adds the image file name to the value of the USTEnabled registry entry (HKLM\Software\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\USTEnabled).
Kernel Special Pool Tags	HKLM\System\CurrentControlSet\Control\Session Manager\Memory Management\PoolTag
Verify Start / Verify End	HKLM\System\CurrentControlSet\Control\Session Manager\Memory Management\PoolTagOverruns. The Verify Start option sets the value to 0. The Verify End option sets the value to 1.
Debugger for an image file	HKLM\Software\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\ImageFileName\Debugger