Windows doesn't provide a renderer for the classic style, you'll have to cook your own. Use the SystemInformation class to get the metrics, Color.FromKnownColor() to get colors.
The only tricky part is to get the frame buttons look good. Best thing to do is to use a glyph from a font instead of trying to paint them yourself. The Webdings font is ideal for this.
I cannot verify how close a match it will be, my machine boots Windows 8 and doesn't support classic style anymore. Otherwise a strong hint that you probably should not invest too much time into this :) Some example code:
protected override void OnPaintBackground(PaintEventArgs e) {
base.OnPaintBackground(e);
var captionHeight = SystemInformation.CaptionHeight;
int border = SystemInformation.Border3DSize.Width;
var color1 = Color.FromKnownColor(activated ? KnownColor.ActiveCaption : KnownColor.InactiveCaption);
var color2 = Color.FromKnownColor(activated ? KnownColor.GradientActiveCaption : KnownColor.GradientInactiveCaption);
var captionrc = new Rectangle(0, 0, this.ClientSize.Width, captionHeight);
using (var brush = new LinearGradientBrush(captionrc, color1, color2, 0, false)) {
e.Graphics.FillRectangle(brush, captionrc);
}
int textx = border;
if (this.Icon != null) {
int height = SystemInformation.SmallIconSize.Height;
var iconrc = new Rectangle(border, (captionHeight - height)/2, height, height);
textx += height + border;
e.Graphics.DrawIcon(this.Icon, iconrc);
}
var color = Color.FromKnownColor(activated ? KnownColor.ActiveCaptionText : KnownColor.InactiveCaptionText);
using (var font = new Font(this.Font.FontFamily, SystemInformation.CaptionHeight - 4 * border, GraphicsUnit.Pixel)) {
TextRenderer.DrawText(e.Graphics, this.Text, font, new Point(textx, border), color);
}
using (var font = new Font(new FontFamily("Webdings"), captionHeight - 4 * border, GraphicsUnit.Pixel)) {
var glyphs = this.WindowState == FormWindowState.Maximized ? "\u0030\u0031\u0072" : "\u0030\u0031\u0072";
var width = TextRenderer.MeasureText(glyphs, font).Width;
TextRenderer.DrawText(e.Graphics, glyphs, font,
new Point(this.ClientSize.Width - width, border),
Color.FromKnownColor(KnownColor.WindowFrame));
}
}
Looks like this on my machine, not entirely ugly :)