"Aero Lite" theme was introduced in Windows 8 testing builds to replace "Windows Basic" theme present in Windows Vista and Windows 7. Aero Lite theme doesn't provide Aero glass and other eye candy effects such as reflection, blur, etc. Its a clean and simple theme created for low-end computers which don't have compatible hardware to support the main Aero theme of Windows 8.

If a computer doesn't have compatible hardware, Aero Lite theme is applied by default in Windows 8. Aero Lite theme was available in Desktop Properties in testing builds but surprisingly Microsoft removed it from Windows 8 RTM i.e. final version.
In Windows 8 RTM, if your computer contains compatible hardware and graphics card, the main Aero theme is applied automatically and Aero Lite theme is not available in Desktop Personalization window. So basically you can't apply and use Aero Lite theme in Windows 8 RTM if your computer system fulfills system requirements of Windows 8.
Now what to do if someone wants to apply Aero Lite theme in Windows 8? How to bring back the Aero Lite theme in Windows 8 RTM? There may be many reasons to use Aero Lite theme such as:
- Windows 8 Taskbar features transparency and there is no option given to disable it. So people can use Aero Lite theme to remove transparency in Taskbar.
- I know many people who use Windows Vista or Windows 7 and always use Windows Basic theme instead of Aero glass theme to save battery time.
- Its always better to have more choices.
Actually Aero Lite theme is still there in Windows 8 RTM but Microsoft removed its .theme file, that's why its not visible in Desktop Personalization window.
Each theme which is shown in Desktop Personalization window, contains a .theme file which is responsible to show its name in Desktop Personalization. If you remove .theme file of a theme, it'll not show in Desktop Personalization window. The .theme file points to the main .msstyles file which contains all the required resources to change UI elements when you apply a theme. Check out following link to read more about themes and msstyles:
[Guide] What is the Difference between Theme, Themepack, Skin, Visual Style and msstyles?
Aero Lite theme's .msstyles file is still present in Windows 8 RTM so we just need to create a .theme file for it pointing to Aerolite.msstyles file and we'll be able to apply it from Desktop Personalization window.
So if you also want to enable Aero Lite theme in Windows 8 RTM, check out following simple steps:
1. Press Win+R keys together to launch RUN dialog box. Now type resources and press Enter. It'll open "Resources" folder in Windows Explorer.
Alternatively, you can open it using Windows Explorer. Just browse through C:\Windows\Resources.
2. Once you open "Resources" folder, double-click on "Themes" folder present in it. "Themes" folder contains all .theme files such as aero.theme, theme1.theme and theme2.theme.

Just check out "aero" folder present in Themes folder and you'll see aerolite.msstyles file which proves that Aero Lite theme is still there.
3. Now we need to create a .theme file for Aero Lite theme. Copy aero.theme file present in Themes folder and paste it on Desktop.
4. Rename the new file to aerolite.theme and open it in Notepad. You can right-click on the file and select "Open with" option and then select Notepad from the list.
Or you can open Notepad and then drag-n-drop the .theme file in Notepad window.
5. When you open aerolite.theme file in Notepad, you just need to change 2 things in the file:
5.a. First change the "DisplayName" value given in 5th line. This parameter contains the theme name which is shown in Desktop Personalization window as mentioned here. Replace the string given after the equal (=) sign to any desired name such as Aero Lite as shown in following image:

5.b. Now we'll need to point this new .theme file to aerolite.msstyles file. Currently its pointing to aero.msstyles file. Scroll down and go to "[VisualStyles]" section. Now replace aero.msstyles with aerolite.msstyles in line 51 as shown in following image:

6. That's it. Save the file and move it to main "Themes" folder which contains other .theme files.
7. Now open Desktop Personalization window and you'll get the hidden Aero Lite theme back as shown in following screenshot:

Click on "Aero Lite" theme icon and get ready to enjoy the theme which was hidden by Microsoft.
NOTE: You can move the new Aerolite.theme file to "C:\Windows\Resources\Ease of Access Themes" folder and it'll show in "High Contrast Themes" section of Desktop Personalization window.
Also check out following topics to read more about hidden and interesting stuff present in Windows 8:
[Windows 8 Review] What's New in Windows 8 RTM Version?
Windows 8 Hidden Secret Features and Useful Hotkeys
PS: If you face any problem in enabling Aero Lite theme, check out following video showing the whole method live in action:
Posted by: Vishal Gupta | Categories: Windows 8
Stannis
Hi! Aside from the taskbar not being semi-transparent, what are the visible differences of this aero lite theme from the default theme?
Asrin475
Awsome VG!
Kyle
That is so cool, Thanks VG you are a REAL hacker!
VG
Thanks guys. ;)
@Stannis
There are many differences. Titlebar buttons, selection boxes and many more. Try the theme and you'll notice them. ;)
alex
just give a download link with the file in a zip please
Someone
Noticed that already, but cool post.
Ashish
Thanks VG
Prabhjot Sohal
Once again
GADAR
NSDCars5
Now I know why MS uses squares. No anti-aliasing needed....
hb860
Hey, nice find!
VG
Thanks guys. I'm glad you found it useful. :)
hb860
Best way to disable useless taskbar transparecny
VG
^^ True.
_alex_
Already noticed that, but never bothered about it, when digging into msstyle to search for Aero Panels, which are removed!
Anyway great tip!
VG
^^ Thanks.
d6k5d3
i can't open that with notepad :( :( :( after opening with notepad it shows weird fonts which no one can understand. how to fix it? would u please post directly the tweaked file so that i can directly put that in the theme folder?
VG
^^ Are you sure you opened .theme file? I think you are opening .msstyles file in Notepad.
delta
Vishal, first this is a good tips. :)
But only just yesterday I got this black title bar and button all over my applications, and that's weird because before yesterday the Aero Lite was fine. Same thing goes on with deleting Aero Lite theme and re-creating it. Then I switched to normal Aero theme and it was fine. How is this happened?
VG
^^ Did you install any patch? Like uxtheme patch, etc?
d6k5d3
thanks a lot vishal :) it was entirely my mistake. yes, i was trying to open .msstyles file in notepad. and finally i got through getting the aerolite theme! :) it works fine and looks very good. thank u once again.
u r aweosme!
Franko
Hey thanks!
lasedan
I don't know if it's a common error or if I am the only one to experience it. After (re)installing Windows 7 I get the following message: "Desktop Window Manager has stopped working". And the computer isn't able to offer me any solution. This causes transparency to stop showing. For all the themes I may want to set up, the taskbar turns to grey. What is it to be done? Could it be an error of my version of Windows set up? Or I could do something to fix it?
Thanks in advance for your answer.
VG
^^ Did you run UXTheme patcher?