Background Intelligent Transfer Service (BITS)

Hi there.

I have a problem with my Background Intelligent Transfer Service (BITS). The
problem probably started with Chemoffice 2006 software that required .Net
Framework 1.1 to work. Then, I installed the Chemoffice 2008 trial that did
not required anything. After then and uninstalling the software, I noticed
that the Background Intelligent Transfer Service (BITS) does not exist in the
services list.
Nothing. It does not exist.

I noticed the problem when the system could not install an update from
Microsoft for Defender.

Any ideas????
Thanks.
I run a windows home premium system.