Try placing this code in your Main method and you should get themed scrollbars

[code]
// Enable visual styles for XP
Application.EnableVisualStyles();

Application.DoEvents();
[/code]

So your main method would look like something similar to below:

[code]
/// <summary>
/// The main entry point for the application.
/// </summary>
[STAThread]
static void Main()
{
    // Enable visual styles for XP
    Application.EnableVisualStyles();

    Application.DoEvents();

    Application.Run(new frmMain());
}
[/code]