Background Intelligent Transfer Service


Background Intelligent Transfer Service (BITS) transfers files (downloads or uploads) between a client and server and provides progress information related to the transfers. You can also download files from a peer.


BITS is most commonly used by Windows to download updates to your local system. If you are an end-user searching for ways to troubleshoot your BITS installation, see the knowledge base (KB) article link at the bottom of this page. If you are seeking to download or re-install BITS 4.0, see KB968929.

Where applicable

Use BITS for applications that need to:

  • Asynchronously transfer files in the foreground or background.
  • Preserve the responsiveness of other network applications.
  • Automatically resume file transfers after network disconnects and computer restarts.

Developer audience

BITS is designed for C and C++ developers.

Run-time requirements

BITS version 4.0 is included in the Windows 7 and Windows Server 2008 R2 operating systems.

You can also download BITS 4.0 for Windows Server 2008 with Service Pack 2 (SP2), Windows Vista with Service Pack 1 (SP1), and Windows Vista with Service Pack 2 (SP2). For information about downloading BITS 4.0, see KB968929.

For information about run-time requirements for a particular programming element, see the Requirements section of the reference page for that element.

For complete version history, see What's New.

In this section

Topic Description
About BITS
General information about BITS.
Using BITS
Procedural guide for developing BITS clients that transfer files between a client and server.
BITS Reference
Reference information for the BITS programming interfaces. Also contains information about samples, tools, server settings for upload jobs, and the upload protocol.
Best Practices
Information to consider when designing an application that uses BITS.

Additional resources

The following are additional resources.

KB articles For a list of Knowledge Base (KB) articles for BITS, see KB331716.
BITS Blog For feature updates, samples, and BITS news, see the Windows Management Infrastructure Blog.
.NET Bits For a set of .NET wrappers for the BITS API, see SharpBITS.NET, at CodePlex.