Definition of scan in The Network Encyclopedia.

What is Scan (in Microsof ecosystem)?

Part of the indexing process used by the Microsoft Indexing Service, an optional component of Microsoft Windows 2000 Server. In Microsoft Windows NT, scanning is made available through Microsoft Index Server. Scanning is the process of inventorying virtual directories on the server that have been configured for indexing to determine whether any new documents have been added that need to be indexed.

How It Works

Scanning can take two forms:

  • Full scans:
    Scan all documents located in the directory


  • Incremental scans:
    Scan only the documents that have been modified since the last scan


If either type of scan finds documents that need to be indexed, the documents are passed to content filters that extract indexing information to form volatile indexes called word lists. This process is called filtering.

Various conditions can trigger a scan of a virtual directory:

  • When a new virtual directory is created and marked for indexing, a full scan is made of the directory.
  • When the NTFS file system determines that a document has been added to a directory marked for indexing, an incremental scan is made of the directory.
  • If documents in a virtual directory are physically located on a non-Windows server such as a NetWare server, Indexing Service periodically polls the server for changes to the contents of the directory; if changes are detected, an incremental scan is triggered.
  • When the system reboots or when the Content Index Service is restarted, incremental scans are initiated for all directories marked to be indexed.
  • You can manually initiate a full scan of a directory by using the Indexing Service snap-in for Microsoft Management Console (MMC).