open File lock

[dheevar]

Hi,

I have a windows 2000 server with SP3.The same is
used as a file server for the users where they access the
files from there.
Once a user opens his file which is on the server and
doing modifications to it he tries to save the same.
Even if the file is closed by the user and later when he
tries to access the same and save it, windows does not
allow him to do so.
If I check the status on the server the file is been
shown as being accessed and the status is displayed
as locked.Even if i restart the client machine the status
remains the same.I have to disconnect all open files
from the server than the user is able to save the file.
Interestingly, the same problem is been encountered
if the file is accessed from a windows 2000 professional
desktop.
is there any resolution to the problem?