Windows 10: GSOD after playing with registry, then unrecognized vol. after restore

I am using Windows 10 insider preview. It was completely healthy until yesterday night and I desperately need help. This is the first time I couldn't fix something and post it online, so please help.

Problem 1: I tried to open a custom guest- account with limited hardrive access. From my personal account (not admin either), I tried to set disk permission. Along with my username and admin and guest-, I noticed a random user like 5890..., a long number. And removed its permissions. While this was ongoing, I saw folders with the the same user (long number) at under HKEY_USERS tab. It didn't permit me for some of them and I clicked OK. Suddenly I get Green Screen of Death --> no code, just a barcode.

Problem 2: It obviously didn't boot and none of the troubleshooting options including System restore blabla would work. I tried to do System Image Recovery as a last chance from a recent image, it failed in the end too. But this time . I can't even access my C: on command drive --> It's letter is shifted to G and partition type became Fat32. Diskpart can't even do anything on it without formatting, and I don't wanna lose my data.


Question 1: What might be going wrong here? Many things?

Question 2: Do I have a way to remove this lock and make the disc accessible for a new Windows installation w/o erasing data?

Question 3: If I hook my C drive to another PC, will it still be inaccessible? If so, how to retrieve it w/o using a search and rescue data scraper program?

Question 4: How about my image backup? It's on another drive. Can I simply erase-format C + install Win and then load the system image of C on itself and voila? Or it's too risky to try? Because I am very sure my Windows had no issues at the time of the image (2wk ago).


Question 5 (optional): Do you guys also think Windows is extremely fragile (1 delete button = GSoD)? I mean shouldn't it have prevented me from deleting those keys? If MS doesn't fix the known issues and keeps recolving the OS around Registry editor, we're likely to see Red screen of death soon, right? The more I keep fixing it the worse the situation becomes, it's like almost a self-virus..

:)

 

How to restore registry values?

Hello,

Thank you for posting your query on Microsoft Community.

You can perform system restore and check if it helps:

Perform System restore.

I suggest you to perform system restore and select a date prior to the changes which was done with the registry values and check if the issue gets fixed.

To perform System restore:

• Press Windows key + X, select
  System.
• In the left pane, click on System Protection.
• Select the option to system restore
  > next. It will show all restore points already created.
• Select the date prior to the date on which you have made the registry changes.

Registry disclaimer

To do so: Important this section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these
steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article
in the Microsoft Knowledge Base:

322756 (http://support.microsoft.com/kb/322756/ )

How to back up and restore the registry in Windows



Try the above step and let us know the status of the issue. We will be glad to assist you further.

Thank you.

 

Registry editing

Hello,

This issue may have occurred after one of the following situations:

• You upgrade the Windows operating system.
• You install or uninstall CD or DVD recording programs.
• You uninstall Microsoft Digital Image.

Given that, we suggest performing the methods in this article:
Your CD or DVD drive is not recognized by Windows or other programs.
The resolutions that are listed in that article may help solve some instances but not all instances of this problem.

Important:This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow
these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, refer to the following Microsoft Knowledge Base
article.

Feel free to update us with the results.

 

registry fix

Hi,

Thank you for posting your query on Microsoft Community.

As per the description, I understand that you are facing some issues using Windows 10.

I would like to know some information.

• 
  What registry fix are you trying to run?
  
• 
  What is the exact issue that you are facing?
  
• 
  Have you taken a backup of all your data?
  

I would suggest you to take a backup of all your data before doing any changes in the registry keys. If you do any incorrect changes to the registry you won’t be able to boot the computer.

Disclaimer: This section, method, or task contains steps that tells you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps
carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in
the Microsoft Knowledge Base:

322756 (http://support.microsoft.com/kb/322756/ )

How to back up and restore the registry in Windows.



Please let us know the information in brief. We will be glad to assist you further.