SQLHDTST is a Win32 file system stress program. Because of the rigorous system demands made by a production database server, sometimes Microsoft SQL Server for Windows NT will uncover problems in the underlying platform.
These may appear as instabilities or other errors. This may be despite the fact that hardware diagnostics run without error, and other use of the system also is without error.
To help isolate these cases, Microsoft Product Support has written SQLHDTST, which is a high-intensity, multithreaded file system stress test. It also exercises the Win32 overlapped, or asynchronous I/O APIs. If it ever detects a problem it will indicate this with an on-screen error. Any problem detected by SQLHDTST means you have a significant platform problem, not a SQL Server problem. These problems can exist at the hardware, controller, firmware, device driver, or operating system layers.