The Registry

Windows NT Registry Objectives

The Registry is not a record of an NT system configuration. It contains values that are not the the system defaults, AKA, data in the Registry -- is the exception. Windows NT supports a maximum registry size of 108 MB.

Hive	Description

HKEY_CLASSES_ROOT	Establishes OLE file associations (retained for backward compatibility)
HKEY_CURRENT_USER	Displays user profile information for the user currently logged in
HKEY_LOCAL_MACHINE	Manages hardware and software configuration, installed drivers, and security
HKEY_USERS	Provides user profile information for all users
HKEY_CURRENT_CONFIG	Displays the currently used hardware profile (a subset of HKEY_LOCAL_MACHINE)
HKEY_DYN_DATA	Provides temporary storage for the state of dynamic events and performance information

Windows NT Registry Tools

Regedit - Explorer interface ; can be used search for keys, values, and data throughout the entire
Registry at once.

REGEDT32 - File Manager interface; can only search for keys. However, REGEDT32 can be used to alter any security settings

Windows NT Registry Backup Tools

Include:

Regedit - Registry > Export Registry File ...
REGEDT32 -
NT Backup cannot backup or restore registry or event log on remote computers. NT can only backup and restore the registry or event logs on the computer where the tape drive is installed. NT Backup can only backup the Registry if you have selected at least one other file. You cannot back up ONLY the Registry.
REGBACK - utility from the NTRK. It is not reliable.

NT Registry Hack Links

Windows NT Tips Tricks and Registry Hacks.
Mega Bite's page of Registry Hacks!

The NT Cache Tweak

How To Modify Your NT Cache

Changing the registry settings for the second-level data cache of Windows NT Server 4.0:

HKEY_LOCAL_MACHINE\ SYSTEM\ CurrentControlSet\ Control\ Session Manager\ Memory Management, in the field SecondLevelDataCache

The change can be made either in decimal by entering 512 or in hexadecimal (base 16) by entering 200. If you enter 512, NT will convert the value in the field to 200h

Previous value was 0 hexadecimal.

"Statistically insignificant change in calculation-intensive performance: an increase of roughly 0.5% in the speed of memory and processor-intensive, math-heavy functions. But disk-intensive operations improved much more. Performance on a randomized disk read and write benchmark rose 10%; benchmarks that hit a more constant file source jumped between 10% and 25%."

This phenomenon has to do with the amount of second-level data cache on a Pentium Pro or Pentium II chip. Early versions of the Pentium Pro had only 256 Kbytes of such cache, but most new systems based on either chip come with 512 Kbytes.

NT is supposed to detect the amount of cache and optimize its usage during disk-intensive operations, but it may not be doing so. Changing the registry setting for the cache to 200h, which is 512 in base 16, apparently forces the operating system to use all 512 Kbytes.