I think profile database is not updating properly.Because of that its taking
Local user administrator  name...Please chk your able to access AD Accounts
properly ?

Actually my situation is:

I am doing an application that will watch a particular directory /folder
(FileSystemWatcher) and upload the files and folder that are added or modified
in that directory to the share point server.

The files are uploaded  to the server  correctly.But with author  name of the
document as the server systems logged  on 's name not the user's name who had
created that file in the client machine.

Is it anyother way to explicitly specify the author and lastmodified name of a
document in the sharepoint  site.

The files will always appear with the name and details of the user that did the
upload. Sounds like in your case you are doing this as the "administrator". If
you want the original file owners name to appear, you will have to impersonate
that user when uploading the files to the document  library.

Please check if you are logged  in with the admin account or some other
account. Try to clear your cache/cookies of IE browser and go to Tools --
Internet Options -- Security -- custom level -- scroll to User authentication
at the end -- check for 'Prompt for user name and password'.

Now try to give your NT account/pwd to login to sharepoint.

My problem is:

I am doing an application that will watch a particular directory
/folder (FileSystemWatcher) and upload the files and folder that are
added or modified in that directory to the share point server.

The files are uploaded  to the server  correctly.But with author  name of
the document  as the server systems logged  on 's name not the user's
name who had created that file in the client machine.

Is it anyother way to explicitly specify the author and lastmodified
name of a document in the sharepoint  site.