When you uninstall Background Intelligent Transfer Service (BITS) 4.0, all current "BITS transfer jobs" in the queue are lost. Additionally, files that have not yet completed downloading are unrecoverable together with their associated temporary files that are occupying disk space until they are explicitly deleted. Therefore, we recommend that the BITS 4.0 package not be uninstalled when there are jobs in the BITS queue.
Uninstalling BITS 4.0 will downgrade BITS from BITS 4.0 to BITS 3.0.
The BITS job queue can be explicitly cleared by using the following BITSAdmin command:
bitsadmin /reset /allusers