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

Here's another possible cause I've found:

There is a bug in Windows 7 and likely in Windows Server 2008 (possibly 64bit versions only). It surfaces when you disable Application Experience service and causes the same problems as described in the question.

Re-enabling this service has fixed this problem for me.

A bit more info here as to why it's causing a problem.

List of other SO questions which seem to be related:

• Visual Studio output file permissions?
• Windows 2008 R2 - Kernel (System Process PID=4) is locking files and folders

Answer 2

For me, it was "Windows Defender" (anti-virus). I excluded my Visual Studio build folders from Windows Defender's list of folders it checks, and the problem went away. (Visual Studio wasn't able to build to the EXE file, PID 4 was locking it to check for virii)