Audio Driver Help

Hello everyone,I need a little help. I am getting ready to start a new at home job.For some reason they are telling me the headset is not compatible to my system because of the audio drivers.I have Sigma Tel High Definition Audio CODEC..They told me it was because of the high definition audio that was blocking it from working on their system.Everything else works on their system is just the headset. Which I really need for the job...So is there a way I could change my audio sound or change it from high definition?Talking about drivers and things of that nature is out of my league..lol..I need to find something else that will work that is not high definition. BTW I have a Dell Dimension 5150/E510 I have checked their site and nothing there for me to try.

Thanks for reading,just a little bit of insight would go a long way Thanks.