windowsxp not Microsost Genuine advan.

Why has microsoft Hijacked My computer with KB905474. I can’t remove it and It will not go away. I bought my computer from a well respected local dealer. I thought. He was at the stripe mall for 18 mounth and moved wothout notice. now I am stuck in the mud with microsoft locking my CDrom and and burner locked out of my system, they say that they are working ok, not so.
SOMEONE PLEASE HELP…..