Running a Process Monitor trace of the file download starting showed that the CreateFile
calls to write to the Temporary Internet Files directory were failing with the error code of DELETE_PENDING
. Process Monitor was filtered such that the Path contains the name of the file being downloaded.
Process Explorer showed open handles to the Temporary Internet Files directory opened by svchost
running the Roaming Profiles service. Restarting the service released the handle, allowing IE to properly write the file.
No further issues with downloads were reported.