Thank you in advance,
Tan

HKLM\System\CurrentControlSet\Control|RegistrySizeLimit

Its a DWORD entry in BYTES

RegistrySizeLimit REG_DWORD 0x0 | 0x00040000–0xFFFFFFFE | 0xFFFFFFFF bytes

Default: 0x0

Establishes the maximum amount of memory and disk space that can be consumed by the Registry. You can add this value entry to the Registry to override the system's calculation of an optimal Registry size limit. RegistrySizeLimit only establishes a maximum size for the Registry. Unlike other limits, it does not allocate or reserve space for the Registry.
Registry size is limited to prevent the Registry from consuming space needed by processes. The value of RegistrySizeLimit applies to space in the paged pool, to disk space for the paging file and files where Registry data is stored, and to space used by some of the Registry's run-time structures. Other Registry run-time structures are governed by their own size limits or by other means.

If the value of this entry is 0x0, or if this value entry does not appear in the Registry, the system adjusts the value of RegistrySizeLimit dynamically based upon the size of the paged pool. This results in an optimal setting for most computers.
If the values of both RegistrySizeLimit and PagedPoolSize are 0x0, the system calculates an optimal value for both entries. Typically, the system sets the value of PagedPoolSize approximately equal to the amount of physical memory on the computer, and sets the vaue of RegistrySizeLimit to approximately 25 percent of the value of PagedPoolSize.

If the value of ths entry is greater than 0x0 and less than 0xFFFFFFFF, the value will be used as the Registry size limit. The system will not calculate an optimal size limit or adjust the size limit when the amount of memory or the size of the paged pool changes.
If the value of this entry is 0xFFFFFFFF, the system sets the the value of RegistrySizeLimit equal to 80 percent of the size of the paged pool.

Notes

Windows NT does not add this value to the Registry. You can add it by editing the Registry or by using a program that edits the Registry.
You must restart the system before a change to this value takes effect.
To ensure that a user can always start the system and edit the Registry, the size of the Registry is not subject to the maximum set in RegistrySizeLimit until after the first successful loading of a user profile.

Tip

To add or change this value, in Control Panel double-click System. Click the Performance tab, click Change in the Virtual Memory box, and then enter a value in the Maximum Registry Size box.

Technical Reference to the Windows NT Registry © Microsoft Corporation 1985 - 1997

Hope this helps

[ 04 September 2001: Message edited by: DGrayOne ]

Because by default the PagedPoolSize value approximately equal to the amount of physical memory and RegistrySizeLimit value calculated by approximately 25% of the value of the PagedPoolSize, then in my point of view, that’s not really illustrate on how much space that we want to reserve safely for the registry, because it is possible that current registry size has reached or even greater than 25% of the amount of physical memory approximately. So I think it is more reasonable to set the maximum registry size limit base on current registry size consumed.

The purpose of setting this value is because when I want to do the automation of updating Emergency Repair Disk on WinNT 4.0, it always show me an error that I have run out of registry quota, or for Internet Explorer automate installation, another example.

Thank you again,
Tan

quote:

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Dureg.exe: Registry Size Estimator
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DuReg is a command-line tool that enables you to discover how much data is stored in the registry, or in any registry subtree, key or subkey. Additionally, the tool also enables you to search for all occurrences of a text string in the registry. This search can be limited to a specific subtree.

Note

DuReg counts data, not space. Because the space any data occupies varies with the storage method and amount of free space available, the size of data and size of space consumed are not equal. Also, because it measures data, DuReg does not account for fragmented free space in the registry.

The DuReg helps developers and administrators estimate how much space registry data is consuming. Developers can use this tool to discover how data they are contributing to the registry. Administrators can use this tool to investigate which applications are filling a registry when the registry approaches its maximum size.

The registry data size function is unique to each system. You can determine the maximum registry size and an estimate of the current registry size by using System in Control Panel. You can also find the current:maximum size ratio (expressed as a percentage) by using the System: % Registry Quota in Use counter in Perfmon\Sysmon. However, only DuReg returns the size of individual keys and subkeys.

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