This policy setting limits the amount of time that Background Intelligent Transfer Service (BITS) will take to download the files in a BITS job. The time limit applies only to the time that BITS is actively downloading files. When the cumulative download time exceeds this limit the job is placed in the error state. By default BITS uses a maximum download time of 90 days (7776000 seconds). If you enable this policy setting you can set the maximum job download time to a specified number of seconds. If you disable or do not configure this policy setting the default value of 90 days (7776000 seconds) will be used.
Network\Background Intelligent Transfer Service (BITS)
At least Windows Vista