Here are screenshots:
Auto-Hidden Folder Band:

After Hovering Mouse over Folder Band:

To make the “Folder Band” Auto-hide in Windows Explorer, you’ll have to edit the “Shellstyle.dll” file which you can get in your currently used theme folder. For example, if you are using default Window Vista theme, then you’ll get the “Shellstyle.dll” file in following directory:
%windir%\Resources\Themes\Aero\Shell\NormalColor
So here is a step-by-step tutorial:
1. First open the “Shellstyle.dll” file in Resource Hacker.
2. Goto “UIFILE -> 1 -> 1033“.
3. Press <Ctrl>+F or click on “View -> Find Text…“.
4. Now type “<style resid=”FolderBandStyle”>” (without quotes) in “Find what” textbox.
5. It’ll let you go to following line:
<style resid=”FolderBandStyle”>
<Element
background=”argb(0, 0, 0, 0)”
/>
Now press <Enter> after “<style resid=”FolderBandStyle”>” line and add following line:
<if mousefocused=”false” mousewithin=”false”><Element padding=”rect(0rp,0rp,0rp,-28rp)”/></if>
So now it’ll look like following:
<style resid=”FolderBandStyle”>
<if mousefocused=”false” mousewithin=”false”><Element padding=”rect(0rp,0rp,0rp,-28rp)”/></if>
<Element
background=”argb(0, 0, 0, 0)”
/>
6. Thats it. Now click on “Compile Script” button and then save the file.
7. Log off or restart to see the changes.
Now Folder band will be auto-hidden and whenever you’ll hove the mouse over it, it’ll appear.
Credits goes to U.K.Intel…