When you turn on background recording, it keeps track of the last few moments of gameplay so you can capture the magic before it’s gone forever.
To adjust the length of background recordings, go to Start > Settings > Gaming > Captures. With Background recording turned On, select the time period for Record the last [time period].
Note: Background recording can affect game performance. If you notice a difference in your game after changing the background recording setting, you might want to pick a shorter recording time.