Export GridView to Excel (xlsx, Excel 2007 Format)

[walter]

Hi
I have my application running in Windows 2000 and uses Office 2000.
Below is the code wrriten to export excel file
Response.ContentType = "application/vnd.ms-excel"
If i try to run the same code in VISTA or XP Machine which uses Office 2007.
I am getting below error.
"The format not supported ... " what it could be the cause and how to
resolve this.
Irrespective of Windows 2000 (Office 2000) , VISTA (Office 2007) or
XP(Office 2007).
Do i need to write any specific code for each OS i use or a single code
which can fix my problem.

Kindly help in this

Thanks
Mwalter.