100% CPU utilization

Hi All,
I am in a small problem so hope to get some answers from the brainy people.
I have one application which using which i can send some data transfer to one handheld device. Now my requirement is even if the CPU load is 100%( using task manager i can see) my application should be abale to do the data transfer. can anybody give me some pointer how to go about this? I have seen some API which can reduce the tasks priority but i am not sure about my appraoch. Hope i am clear with my question. Waiting for the helping hands…..

regards
Anks