Accidentally deleted some registry values...

[Delnar_Ersike]

Well, yesterday I was tinkering with some third-party program utilities on Windows XP and accidentally deleted some registry values I later realized I shouldn't have. This isn't such a big deal, as the registry values that were deleted were all startup values, so I guess they are easily replaceable. XFire and BitTorrent are especially easy, as all I had to was check a box and it was replaced. However, some pretty important driver startup registry values were also deleted (like the wireless network adapter and the system tray) that I wish to bring back. My question: how can I bring back most of the important startup registry values?

[Harrierfalcon]

It sounds like the program data is there, but it's not "registered with Windows". This is a frequent problem I've run into after the X number of system restores I've gone through, and the only solution I've found is to reinstall.

[NETWizz]

Some of this taken from http://support.microsoft.com/kb/307545. I just adapted that article to your particular need.

Your registry values still exist in the System Restore Points.

1. Start Windows Explorer.
2. On the Tools menu, click Folder options.
3. Click the View tab.
4. Under Hidden files and folders, click to select Show hidden files and folders, and then click to clear the Hide protected operating system files (Recommended) check box.
5. Click Yes when the dialog box that confirms that you want to display these files appears.

C:\System Volume Information is not accessible. Access is denied.
If you receive this message, see the following Microsoft Knowledge Base article to gain access to this folder and continue with the procedure:
309531 (http://support.microsoft.com/kb/309531/) How to gain access to the System Volume Information folder

Sort the system restore points by date.

They look much like this:
C:\System Volume Information\_restore{D86480E3-73EF-47BC-A0EB-A81BE6EE3ED8}\RP1\Snapshot

Find the newest one that is before you messed up the registry and have a peak inside. You will find the following files:

• _REGISTRY_USER_.DEFAULT
• _REGISTRY_MACHINE_SECURITY
• _REGISTRY_MACHINE_SOFTWARE
• _REGISTRY_MACHINE_SYSTEM
• _REGISTRY_MACHINE_SAM

SOFTWARE is of particular interest as it is HKEY_LOCAL_MACHINE\Software when loaded in regedit.

SAM is security accounts manager...

Regardless, here is what you should copy the needed file to your desktop or another safe location.

Open Regedit and select "Load Hive" from one of the menus ( I am not in regedit now) Point it to a file and give it a name.

I.e. HKEY_LOCAL_MACHINE\bob and have something like the SOFTWARE hive from system restore on it. Think of this as mounting and unmounting registry hive files as if they are file-systems. That is essentially what you are doing.

Then go into the hive file and find the needed values and export them to a .reg file that you save somewhere like your desktop. Before exiting regedit, unload the hive you loaded.

Open the .reg file in notepad or other text editor and use Find/Replace.
Find HKEY_LOCAL_MACHINE\bob
Replace with HKEY_LOCAL_MACHINE\SOFTWARE

Replace all and save.

Double-Click and merge the .reg with your registry. It will merge all exported values you have taken from the system restore backups with the running registry.

You can also preceed a branch with a -

[-HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run]
... Rest of text file here

That would delete and replace an entire registry branch with one recovered from a snapshot.

Basically, what I am saying is that you probably have a backup of your entire registry and you can easily restore values.

-NETWiz

[Delnar_Ersike]

Thanks for the info Harrier and NETWiz. I did what you said, NETWiz, but I am stuck at this step:

[NETWizz]

Click on HKEY_LOCAL_MACHINE

Then, File > "Load Hive"

[Delnar_Ersike]

That is what I did, it was grayed out aka I couldn't select it.

Ah well, just fifteen minutes ago my computer froze and I was forced to restart it. After a couple of tinkering in safemode and accessing the same third-party software via my dual-boot Ubuntu, I was able to successfully boot into Windows and run a couple of stuff without getting a blue screen of death. However, some of my drivers have screwed up in the process: my trackpad can't use the scroll wheel function, some icons are missing from the system tray (including the trackpad, task manager, and xfire), and my driver update files are going completely wacko (they can't identify the model of my computer, for example). But other than those minor issues, everything is fine (good thing that third-party software had a built-in registry restore).