How to delete a record in ASP.net using SQL Server 2005

Create a command object, write a delete query and execute the query using command object. There are many other ways. But I don't think this is what you exactly want. You need to more specific and describe your scenario properly to get a better answer.
UPDATE:
OP wrote: Sir There is one button named DELETE and when i highlighted a record using a gridview and click the button, it will be automatically deleted. Is it possible? Now i can only view it via gridview
You could have easily found the examples using Google/Bing. Here are few:
MSDN - GridView Examples for ASP.NET 2.0: Deleting a GridView's Underlying Data[^]
CodeProject - GridView Delete, with Confirmation[^]
CodeProject - Insert, Update, Delete with Gridview....simple way[^]

I found all of them by doing this[^].

Without using gridview..

'Add following Namespace
using system.data;
using syste.data.sqlclient;

'Write on delete buttons click event

string query = "delete from tablename where primarykeycolumnname = value";
SQLConnection con = new sqlConnection('your connection string);
SQLCommand cmd = new SQLCommand(query, con);

try
{
    con.Open();
    cmd.ExecuteNonQuery();
}
catch
{
   'Handle Exception
}
finally
{
     con.Close();
}

and for gridview write the above code in the rowdeleting event

but the primarykeyvalue in the query will come from the follwing code

first of all set the datakeys properties of the gridview to primary key value

and now access the same for eg say ID is the primary key
so you can get its value in rowdeletingevent as

int value = gridview1.Items[gridview1.selectedIndex].value.tostring();

following the code above