This post will serve as a guide for those trying to fix the Change PC Settings button in the Charms bar. I recently ran into a problem where the Change PC Settings button simply wouldn't respond when I clicked it, either when booting normally, or when in Safe Mode. I was able to fix the problem on my machine without having to use the Refresh option, or completely format and start over, as I saw so many others doing while researching the issue. Here I will take you through the entire process I went through to get the issue resolved. If it doesn't work for you, please post a new thread and describe your problem in as much detail as possible.
Part 1: Discovery
This is where you first stumble upon the problem. Make sure you note exactly how the button behaves when you click it, as noted below.
If the button simply does nothing when you click it, move ahead to step 2a.
If the button responds, but fails to bring up the Change PC Settings screen, instead kicking you right back to the main Start Screen you see when first booting, move to step 2b.
Part 2: Making Repairs
For this, you will need a couple of tools depending on the exact nature of the issue. If you need to read this, you will definitely need a new copy of the Change PC Settings shortcut that the button in the Charms bar uses to launch the Change PC Settings screen.
2a. A copy of the shortcut is available here. Extract the shortcut in the zip file to C:\ProgramData\Microsoft\Windows\Start Menu\Programs. Now go back and try the Change PC Settings button again. If it works, congrats! If it kicks you back to the main Start screen instead, continue reading...
2b. If it launches the Start screen instead of the Change PC Settings menu, you will need an additional program now that the shortcut to the menu is back in place. Go download Sysinternals Process Monitor. Run the tool and immediately press Ctrl + E to stop the capture process (there will be a LOT of irrelevant info displayed during the initial capture). Then press Ctrl + X to clear all of the captured data. Along the bar just underneath the File, Edit, etc. menus, click the buttons the furthest to the right that disable types of events to display (if you hover your mouse over each button, a tooltip will tell you what the button is for) The only one we should leave enabled here is the "Show File System Activity", as shown in the screenshot below:
Now (as quickly as you can, to avoid filling the screen with more irrelevant data), press Ctrl + E to begin the capture process again, and then access the Charms bar and click the Change PC Settings button (the quickest way to do this is press the Windows Key + I on your keyboard and directly click Change PC Settings). You should again be taken back to the Start Screen instead of the Change PC Settings menu. Click the Desktop shortcut on the Start Screen and go back to the Process Monitor window. Press Ctrl + E to stop the capture again.
What is displayed in the window should tell us exactly what file the system is looking for, and where to find it (or where it is supposed to be). For reference, you should see something similar to the image below:
I've highlighted the entry that you should be looking for in the Process Monitor window. In my case, when I went to the path shown in the Process Explorer, I saw that the file trying to be accessed by the system was indeed not present.
Proceed to the C:\Windows\ImmersiveControlPanel\microsoft.system.package.metadata folder, and referring to the data you captured earlier with Process Monitor, make a copy of the .pckgdep and .recovery files you see there (my screenshot had a couple of these with different names.... you may only have one of each), and then rename the copies to the name shown in the Process Monitor window, as shown in my example below:
As soon as you rename the copies of these 2 files, you should be able to access the Change PC Settings window again. No reboot should be necessary.
As I said at the start, if this process doesn't work for you, please post a thread here in the Windows 8 section and we will do our best to help.