Event ID 81 — Configuration

Applies To: Windows Server 2008 R2

In order for BITS to cache downloaded content, peer caching must be enabled for the BITS peer caching server by a domain administrator.

Event Details

Product: Windows Operating System
ID: 81
Source: Microsoft-Windows-Bits-Client
Version: 6.1
Message: BITS has encountered %1 error while starting one or more peer-client or peer-server components.


Restart the BITS service

To resolve this issue, stop and then restart the BITS service. If this does not resolve the issue, contact Microsoft Customer Service and Support (CSS).

To perform this procedure, you must have membership in the local Administrators group, or you must have been delegated the appropriate authority.

To stop and restart the BITS service:

  1. Open an elevated command prompt. To open an elevated command prompt, click Start, right-click Command Prompt, and then click Run as Administrator.
  2. Type sc stop bits, and then press ENTER.
  3. Type sc start bits, and then press ENTER.

For information about how to contact CSS, see Support Options from Microsoft Services http://go.microsoft.com/fwlink/?LinkId=52267.


To ensure that the peer caching client is enabled:

  • From a command prompt running as an administrator, type:


Confirm that the output includes:

  • Enable download from peers: true
  • Enable serving to peers: true


BITS Infrastructure