A virtualization partition (VP) is executed by a virtualization layer. The VP contains guest software that executes in isolation within the VP. The guest software has a background task (BT) that needs to be performed in the future. The BT is virtualized by a BT service that executes outside of the VP. The guest software registers the BT, through the virtualization layer, with a BT virtualization service. An event occurs outside of the VP that triggers the BT. The BT virtualization service responds to the event by assuring that the VP is available (executing), and optionally triggers (possibly indirectly) the execution of code in the application.