Under which circumstances does the System process (PID 4) retain an open file handle?

Question

My application running on a Windows server makes use of a Jet/Access database. For some reasons around every two weeks that database file gets locked by the System process (

Answer 1

This sounds to me like a driver-level issue with a leaky handle.

If you're running an anti-virus package try upgrading, disabling (temporarily!) or switching to a different brand.

Answer 2

For me I had to hit it with a sledgehammer. Chkdsk /f on the drive where the folder was located fixed it. Use with caution.

Answer 3

It may be a lingering session from a remote computer to a shared folder. If that's the case, it can be unlocked from the command line:

net session /delete

Answer 4

Check the security settings for each folder and subfolders. Make sure that the system did not just automatically create a special permissions setting which will not allow anyone to delete the file. Apparently for some odd reason the OS creates a weird special permission setting that protects the file from being deleted.

Answer 5

Is your server set up to perform periodic file backups?

If so, is the backup running as System, perhaps prompting the locked file when you get a conflict?

Answer 6

Files accessed through a share will be locked by the system process (PID 4).

Try opening compmgmt.msc -> System Tools -> Shared Folders -> Open Files to see if the locked file is listed there

See also the sysinternals forum for a way to replicate this.
Not all applications lock files when they are opened, Excel however does. I don't know if Access does the same...