REGISTRY BASICS

The registry contains extended information, settings and various other values for the the Microsoft Windows 95, Windows 98, Windows NT, Windows 2000 and Windows ME operating system. Within the registry you can control a great majority of the operating system as well as fix a lot of issues with Windows. However we only recommend those whom are experienced with computers or whom feel confident to go into the registry.

Before going into the Registry and changing or deleting anything we ALWAYS recommend that you backup the registry.

The computer registry consists of two files hidden in the Windows directory, system.dat and user.dat. User-specific system information is contained in the user.dat file and Computer and Hardware specific information in the system.dat file.

To get into the Windows 95 or Windows 98 registry click Start / Run / type regedit

When typing regedit you will get the following screen this window as you can see is the Registry editor. This windows looks very similar to Explorer however within each folder you have sub folders which have various settings.

The following are the types of files that you will see during the time you are in the registry.

- Open or selected folder just as you would see in Windows Explorer
- Closed folder just as you would see in Windows Explorer
- String Value allows you to place certain values to certain aspects of a program such as a version number.
- Binary Value allows you to set attributes to a particular application, values are in binary.
- Dword Similar to the binary value allowing you to set attributes however done in binary and hex.

BACKING UP / RESTORING THE REGISTRY

Backing up Windows 95 Registry:

To backup Windows 95 Registry from the Windows desktop click Start / Shut Down / Restart the computer in MS-DOS mode.

At C:\WINDOWS> type the following:

attrib user.dat -r -a -s -h <press enter>
attrib system.dat -r -a -s -h <press enter>
md backup <press enter>
copy user.dat backup <press enter>
copy system.dat backup <press enter>

The above will copy the registry files into a backup directory in your Windows directory. Once the above has been done you can restart the computer and edit the registry as needed.

Restoring Windows 95 Registry:

If you by chance make a mistake while in the registry and have done the above, get to a DOS prompt. If you are not able to get into Windows. As the computer is booting up and you see Starting Windows 95 or you hear a beep press your F8 key on the keyboard this should get you into the Windows 95 Startup menu. Choose the option for Safe Mode command prompt only.

When at the DOS prompt type cd\windows (note you will not be able to get into this directory if you have not followed the above steps earlier in backing up your registry.

Once in the Windows directory type the following:

attrib user.dat -r -a -s -h <press enter>
attrib system.dat -r -a -s -h <press enter>
del user.dat <press enter>
del system.dat <press enter>

Once these files have been deleted type cd\windows\backup once in the windows\backup directory type the following:

copy user.dat c:\windows <press enter>
copy system.dat c:\windows
<press enter>

The above should copy two files, once copied reboot the computer and you should now be able to get back into Windows.

Backing Windows 98 Registry:

Windows 98 has a new feature referred to as scanreg that will automatically backup your registry each time you boot up your computer, however the steps listed above for backing up Windows 95 registry also work but are not necessarily need unless you wish to keep an originally un-touched copy of the registry.

Restoring Windows 98 Registry:

To restore Windows 98 registry get into a DOS prompt, if you are not able to get into Windows 98 to shutdown the computer to get into a DOS prompt as the computer boots up press and hold your left ctrl key on your keyboard which should get you into a Windows 98 startup menu, in this menu choose the option for command prompt only (safe mode command prompt only will not work).

Once at the prompt type cd\windows\command

Once in this directory type scanreg /restore this will restore a previously backed up copy of your registry. You then should be able to reboot the computer and get back into Windows.

If you backed up your registry using the Windows 95 steps use the Windows 95 restore steps to restore the registry.

REGISTRY KEYS

KEY

DESCRIPTION

HKEY_CLASSES_ROOT

Points to branch of Hkey_Local_Machine that describes certain software settings. This key displays the same data as it did in Windows 3.1 - essential information about OLE and association mappings to support drag-and-drop operations, Windows 95 shortcuts (which are, in fact, OLE links), and core aspects of the Windows 95 user interface.

HKEY_CURRENT_USER 

This key points to a branch of Hkey_Users for the user who is currently logged on.

HKEY_LOCAL_MACHINE 

Contains computer-specific information about the type of hardware installed, software settings, and other information. This information is used for all users who log on to this computer.

HKEY_USERS

Contains information about all the users who log on to the computer, including both generic and user-specific information. The generic settings are available to all users who log on to the computer. The information is made up of default settings for applications, desktop configurations, and so on. This key contains sub keys for each user that logs on to this computer.

HKEY_CURRENT_CONFIG 

Points to a branch of Hkey_Local_Machine\Config that contains information about the current configuration of hardware attached to the computer.

HKEY_DYN_DATA

Points to a branch of Hkey_Local_Machine that contains the dynamic status information for various devices as part of the Plug and Play information. This information may change as devices are added to or removed from the computer. The information for each device includes the related hardware key and the device's current status, including problems.

REGISTRY SCREEN SHOTS


The Main Windows of the Registry Editor

REGISTRY Q&A

Q: Is there a way to edit the registry from a command prompt (DOS)?
A: Unfortunately because the registry is a part of Windows it is not possible to edit the registry without running Regedit through Windows. If you are not able to get into Windows you may wish to attempt to run regedit.exe from Safe mode.

http://www.winguides.com/registry/