If you want to personalize, customize, and change settings of taskbar in Windows 8, follow these steps:
1) Right click on the middle of the taskbar, where there are no icons and select “Properties”.
2) In Taskbar tab, select option “Lock the taskbar” to lock the taskbar so that you cannot re-size it. If you wish to re-size the taskbar then uncheck “Lock the taskbar”. Now, move your mouse at the edge of the taskbar and when you see the drag symbol, click and hold the mouse and drag the taskbar to the size as per your choice.
3) Auto-hide the taskbar: If you select this option, then the taskbar will be hidden when you are not using it.
4) Use small taskbar buttons: If you select this option, then smaller icons will be used in taskbar.
5) Taskbar location on screen: From this drop down menu, you can select where you need to place the taskbar in your computer. You can place the taskbar on the left side, right side, bottom of the screen or top of the screen.
6) Taskbar buttons: If you select the option “Always combine, hide labels” from this drop down menu then, the similar apps will always be combined to one icon in taskbar. For Example, if there are three instances of Mozilla Firefox browsers open then, they will be combined to one Mozilla Firefox icon. You need to hover over or click on the the Mozilla Firefox icon to see all the instances. If you select the option “Combine when taskbar is full”, then, similar apps will only be combined to one icon if the taskbar is full. If you select the option “Never combine”, then taskbar items will never be combined.
7) Notification area: You can click on “Customize…” to customize the notification icons as per your requirements. For more details on how to customize the notification area in Windows 8, you can refer this post.
8) Use peek to preview the desktop when you move your mouse to the Show desktop button at the end of the taskbar: You can select this option to see the preview of the desktop, when you move the mouse to the bottom right most corner of the screen.
9) When, you are done, click on “Apply” and then “OK”.