5 out of 5 stars.

How to make your Windows system look like Windows XP:
1: Download Bliss;
2: Set it as a wallpaper;
3: Standard pointer, "Twilight" color scheme, transparency off.
There! If you want to downgrade to other systems, like Windows 95/98/2000/ME, you're lucky! Here it is:
1: Classic theme;
2: Standard pointer, dark blue-green/cyan desktop color.
Downgrading to Windows 3.x:
1: Auto-hiding taskbar;
2: Classic/high contrast/contrast black themes;
3: Standard pointer, grey (25%)/black desktop color.

Moving to Mac OS X?
1: Download Aurora;
2: Set it as a wallpaper;
3: Black pointer, "Light" color scheme, transparency off.