The default settings in Windows 7 allow for a 40-45 minute live TV buffer. You can easily change this by editing a few registry values. Open the registry editor and navigate to the following registry key:

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Media Center\Service\Video\Tuners\DVR\

Modify the following values to suit your needs:

  • BackingStoreMaxNumBackingFiles - The maximum number of buffer files to use for the current channel.
  • BackingStoreMaxExistingBackingFiles - The maximum number of buffer files to use for all channels.
  • BackingStoreEachFileDurationSeconds - The length, in seconds, for each buffer file.


  1. The values in BackingStoreMaxNumBackingFiles and BackingStoreMaxExistingBackingFiles do not include the file WMC is currently buffering. So if those two values are 8, a 9th file is used as a "current" buffer file, while the other 8 are "previous" buffer files.
  2. The minimum allowed value for BackingStoreMaxNumBackingFiles and BackingStoreMaxExistingBackingFiles is 4. The minimum allowed value for BackingStoreEachFileDurationSeconds is 5.