Chapter 13
Tuning The Registry

•  Understanding The Registry

•  Navigating With The Registry Editor

•  Setting Permissions On Registry Keys

•  Auditing The Registry

•  Repairing A Damaged Registry

•  Useful Registry Keys

The registry is Windows NT Server’s internal database and is probably the most critical file on your server. The registry contains all of the configuration information required by Windows NT Server. This configuration information includes specific switches for the various services (server, workstation, etc.), hardware settings (interrupts, I/O ports, DMA channels, etc.), all user and computer accounts, all security restrictions, all performance-related data (although performance-related data is stored in a memory resident key), and various other odds and ends. If it is configuration or information related, you can probably find it in the registry. Should your registry become damaged, Windows NT Server may not function correctly. In the worst case example, Windows NT Server may not even boot. Most Windows NT services or applications provide an interface to the registry so that you can modify the configuration settings without directly accessing the registry. Unfortunately, not all configuration settings or informational items are accessible without using the Registry Editor.

Depending on how you installed Windows NT Server, you may have different versions of the Registry Editor. If you installed Windows NT Server in a dual-boot configuration over Windows 3.x or Windows for Workgroups, you will have the 16-bit version of the Registry Editor called REGEDIT.EXE and a 32-bit version called REGEDT32.EXE. On the other hand, if you installed Windows NT Server to a clean hard disk, you will have a 32-bit version of the Registry Editor called REGEDIT.EXE and another 32-bit version called REGEDT32.EXE. REGEDIT.EXE is the new version of the Registry Editor (see Figure 13.1) while REGEDT32.EXE is the old Registry Editor (see Figure 13.2) provided with prior versions of Windows NT Server. The primary difference between the two 32-bit versions of the Registry Editor is that REGEDIT.EXE provides the same user interface as the Windows 95 Registry Editor. Unfortunately, the new Registry Editor is missing a few key features. It does not support setting, removing, or modifying the security attributes on a registry key. It does not support auditing a registry key. And, it doesn’t display or support the native registry key data types in the same fashion as does REGEDT32. EXE. For these reasons, I prefer to use REGEDT32.EXE, and the rest of this chapter will be based on this version of the Registry Editor.

Figure 13.1  The new 32-bit Registry Editor.

Figure 13.2  The old 32-bit Registry Editor.

---

TIP:  One beneficial aspect of the 32-bit version of REGEDIT.EXE is that it supports searching the registry by keys, value, or data. If you need to find a specific entry in the registry, this is the way to do it because REGEDT32.EXE only supports searching by key.

---

The Registry Editor is not an officially supported application, although Microsoft has made it available as a tool to help you when you call for technical support. This is why you will not see the Registry Editor in any of your Program Manager groups. However, I find this tool so useful that one of the first things I do after I have installed Windows NT Server is add this tool to the Administrative Tools group. You can do this, as well, by creating a new program item for the Administrative Tools group and specifying Registry Editor for the description and REGEDT32.EXE for the command line.

---

WARNING:  The Registry Editor is a very powerful tool. You should use extreme care when using this tool because the configuration information for Windows NT is stored in the registry (in binary format), and if you inadvertently delete a required registry key or value, it is possible that Windows NT will refuse to load. Your only recourse will be to restore the original registry using the repair process or a recent tape backup.

---

Before you start hacking away with the Registry Editor, I think an explanation of the registry is in order. Once we have that out of the way, we’ll take a look at the Registry Editor and how to use it. Then, we’ll pinpoint some of the registry keys that we can use to modify the configuration of various services, we’ll talk about how you can repair a damaged registry, and we’ll review some useful registry keys that might come in handy down the road.