Lenovo Laptop Y410 — Its sound system

Complaint For Lenovo Y410 Laptop‏
Hi,

I am Pallavi. My father had purchased one lenovo laptop from SOFTNET INFOSYS PVT. LTD, PATNA, BIHAR on 09/01/2008. My lenovo laptop S/N is MA-8N05T and Model Name is 7757-54Q. Now, this laptop has very big sound problem. I am very desperate of this. More over what i had heard about the sound quality of the LENOVO LAPTOP is not upto the mark.when I contacted the shopkeeper, They said me the reason of VISTA OPERATING SYSTEM.
Finally, till today i am not satisfied with its sound quality

Now my stand is what's the use of LENOVO in comparision to others.
I have all the receipts with me. I don't know whom to contact but I am sure if you people take up my request forward I surely get positive response from them. Please find the below details of Laptop

Company : Lenovo
S/N No. : MA-8N05T
Model No.: 7757 54Q



Thanks
Pallavi, Patna.
Contact No. [protected]/[protected].