Right click on taskbar > properties > make sure use aero peek preview is checked. Go to personalize and select an Aero theme.
Lastly, if that doesn’t fix the problem, make sure that your display settings for Windows is set to Aero Theme. Flip 3D was also removed Win + Tab was changed to switch between Metro-style apps. Transparency effects were removed from the interface, aside from the taskbar, which maintains transparency but no longer has a blur effect. The Aero Glass theme was replaced by a flatter, solid colored theme. If the problem is automatically fixed, the window borders are translucent. Click Advanced if you want the problem fixed automatically, and then click Next to continue.
