Choosing a Registry Editor
You might wonder which Registry editor to use. Each Registry editor has
advantages and disadvantages, and I use both editors depending on the situation.
Regedt32. Regedt32 has a security feature that regedit
lacks. You can use regedt32 in a read-only mode: Start regedt32, and select Options, Read Only Mode. Working in the read-only mode prevents you from accidentally making changes as you search through the Registry.
As I mentioned previously, regedt32 can search in only the current subtree. But, regedit can't handle multiple-valued strings or strings that contain variables. Thus, I use regedt32 to make Registry changes when I know the Registry path.
Although regedt32 can't search for a Registry value, you can use an
old NT 3.x workaround to this problem. Use the print option to print
a Registry subtree to a file, then use Notepad or WordPad's text search to find the key. Make sure you use the print option rather than the save option, because regedt32 saves Registry keys in a form that text editors can't read.
Regedit. Regedit has better search capabilities than
regedt32 has. Regedt32 can search only for a key--not for a value within the key. Regedit searches for keys, values, or data throughout the entire Registry, so you don't have to know which subtree to look in. Press Ctrl+F or select Edit, Find to open a search window. When regedit finds the value you want, it shows the entire path.
Proceed with Caution
Before you edit the Registry, you need to take some precautionary
steps. First, make sure you have an up-to-date Emergency Repair Disk (ERD). Second, make sure you have a backup of the Registry. If you save a Registry key before you modify it, you can easily restore the original if your change doesn't work as intended. You can use the rdisk utility to create a backup, or you can use regedt32 or regedit to create a backup. You can use either Registry editor to back up all or part of the Registry. In addition, you can use the Registry editors to restore the Registry.
Go Ahead, Make Those Changes
Administrators commonly make two types of modifications to the Registry:
changing an existing value and adding a new value. The simplest modification you can make is changing a value. You typically know the complete path of the value you need to change, and you simply find the value and make the change.
If you change a value with regedt32, you need to select the correct mode, because regedt32 displays values as decimal, hex, or octal. For example, suppose you enter 10 as an interrupt for your network card. If you're in decimal mode, you'll have no problem. But if you're in hex mode, typing 10 requests interrupt 16, and the network card doesn't start. Screen 3 shows the Registry entry for the EventLog file's size: 0x80000 in hex or 524288 in decimal. In cases in which the value can be only 0 or 1, the mode you're in makes no difference. I sometimes see students in NT classes unnecessarily change from the default hex mode to decimal mode before they change a value from 0 to 1.
Adding a value with regedt32 is slightly more complicated than changing a value. Start regedt32, and select Edit, Add Value. You need to supply the name of the value, the type of value (e.g., REG_DWORD), and the actual value. Make sure you enter the name and type of value correctly. After you close the Registry editor, your changes will take effect.
Action at a Distance: Editing the Registry Remotely
As an administrator, you can connect to remote computers and edit
their Registries. Both Registry editors let you make remote changes.
You can't see the HKEY_CURRENT_CONFIG and HKEY_DYN_DATA aliased subtrees
on remote systems, but you don't edit these subtrees anyway. Regedt32 shows only the HKEY_LOCAL_MACHINE and HKEY_USERS subtrees. You typically make changes only to the former to troubleshoot a system problem. On the latter subtree, the regedt32 window shows the computer name (instead of
HKEY_USERS on Local Machine) to indicate which computer you are
connecting to, as Screen 4 shows. The regedit window shows a more Explorer-like interface, as you see in Screen 5.
Don't Be Afraid of the Big Bad Registry
Some administrators worry so much about making changes to the Registry that they neglect numerous opportunities to tune NT and improve their system performance. Don't let the Registry scare you. If you browse in read-only mode and you take the proper backup precautions, you have nothing to fear.