What is the function of Background Intelligent Transfer service ?
BITS is most commonly used by Windows to download updates to your local system.
You can get more information about it here
Why do you like to stop this service? And how to stop it?
Reason is very simple,it consumes lots of bandwidth.As a result internet speed becomes slow.At the background it always consumes network’s major share and makes download speed or opening of a webpage crawling.Press Ctrl+Alt+Del tabs to open Task Manager.Under the Processes tab you will find Service Host:Local System is consuming lots of network bandwidth. If you expand this you will find BITS is running under this.Right click on it and select Stop process. You will observe the network bandwidth change immediately.
In the Start Search type in msconfig and hit the Enter key.
Now click Services tab and scroll down to locate Background Intelligent Transfer service. Uncheck the box against it. Click Apply and restart the system to execute the changes.
In the Start Search type in services.msc and hit the Enter key.Locate Background Intelligent Transfer and right click on it to select Properties.If the service is running , click Stop tab.Click Ok/Apply.
Via Registry edit:
In the Start Search type in regedit and hit the Enter key.
Locate the following registry location:
locate Start registry key .Double click on Start and edit the value to 4 (disabled)
Close Registry editor and restart.