If you’ve uninstalled program in Vista from Control Panel, perhaps you’ve noticed a tasks “Turn Windows features on or off” at the left pane. When you click on it, Windows Features dialog will appear asking you to “Please wait” and it will start searching for a list of windows features such as games, indexing service, internet information services (IIS) and etc that you can turn on or off. Vista Windows Features is actually pretty much the same as Add/Remove Windows Component in Windows XP. You can also run Windows Features by typing optionalfeatures.exe at run or command prompt.
Blank or Empty Windows Features
One of the most common problem that many people are facing with the Vista Windows Features is the dialog box came out empty or blank. You can see “please wait” initially as it tries to make up a list but then it totally blanks out. Microsoft of course is aware of this problem and they’ve created a knowledge base 931712 to acknowledge the problem and also provided 2 solutions to resolve this issue. First method is to run sfc.exe /scannow command to scan all protected system files and replaces incorrect versions with correct Microsoft versions. If that didn’t work, you’ll have to do a System Restore. I also found another method in Google that claims to fix it by running the following command “reg delete HKLM\COMPONENTS /v StoreDirty”. I assure you that these solutions don’t work. The only known solution that will fix the blank Windows Feature is to reinstall Windows but then most manufacturer only provides recovery disc and no installation disc. Don’t worry because I found a REAL fix for the empty Windows Features problem without reinstalling Windows.

1. Download System Update Readiness Tool from Microsoft. Scroll right to the bottom of the page and download the correct version of this tool according to your operating system.

2. Once finished downloading, close all running programs and run Windows6.0-KB947821-v4-x86.msu. Click OK to install KB947821 update for Windows. You will see that it is as though trying to install an update but actually it is trying to fix any problems that it finds on the system in background using checksur.exe. This will take a while, so you can go and have a cup of coffee.
Install kb947821 update

3. When installation completed, click Close and restart your computer.

4. Once Windows is booted up, try running Windows Features (optionalfeatures.exe) and see if the list is loaded or not. IF not, continue the next step.

5. Go to Windows\Logs\CBS\ and open CheckSUR.log file with notepad. The following steps are going to be a little tricky because everyone gets different result.

6. Take note of the part that says “Checking Package Manifests and catalogs” in the CheckSUR.log file. If there are errors, you will see a line with (f) followed by error code and path. If you see (fix), it means the tool manage to fix that particular error.
Analyzing CheckSUR.log file
As you can see, the fourth and fifth (f) lines are not fixed as it continues checking the next watchlist.

7. Now you’ll need to manually delete the registry keys according to what you see in the CheckSUR.log file. Run regedit and go to the following location.
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Component Based Servicing\Packages\

As an example, I see Package_5_for_KB938979~31bf3856ad364e35~x86~~6.0.1.2.mum on my CheckSUR.log file. So I need to look for the key in registry at the location that I stated above and then delete it. There won’t be a .mum extension on the registry. As long as the whole line matches without the extension, you can delete it.

8. You will need to set full control permission before you can delete the corrupted registry key. Refer to this article on how to set the permission.

After deleting the corrupted registry, I am very sure your Windows Features will start to show the list. The good thing about running System Update Readiness Tool is it might have already fixed some problems which probably you are not aware of. I have copied System Update Readiness Tool to my flash drive because it is a potential utility to fix problems in Vista.

[tags]optionalfeatures, blank, empty, vista, features[/tags]