Increase in Hard Disk Space Usage After Windows 2000 Upgrade

ID: Q244861

The information in this article applies to:

Microsoft Windows 2000 Professional
Microsoft Windows 2000 Server
Microsoft Windows 2000 Advanced Server

IMPORTANT: This article contains information about editing the registry. Before you edit the registry, make sure you understand how to restore it if a problem occurs. For information about how to do this, view the "Restoring the Registry" Help topic in Regedit.exe or the "Restoring a Registry Key" Help topic in Regedt32.exe.

SYMPTOMS

When you upgrade to Windows 2000, your computer may use more hard disk space.

CAUSE

This behavior can occur because the Windows File Protection (WFP) feature in Windows 2000 stores copies of system files in the Dllcache folder on the boot volume.

STATUS

This behavior is by design.

MORE INFORMATION

WFP prevents shared system files from being overwritten by non-operating system installation programs. By preventing the replacement of essential system files, file version mismatches can be avoided. WFP runs in the background on a Windows 2000 system.

Windows 2000 maintains backup (cached) versions of all these files in the Dllcache folder. The limit of the space that the cache uses is specified in the following registry key:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\SFCQuota

If FFFFFFFF is specified, all system files are cached in the Dllcache folder. WFP adds files to the cache until the size of the Dllcache folder reaches the SFCQuota value, or until the free space on the volume is 150 MB or less. All .sys, .dll, .exe, and .ocx files that are included on the Windows 2000 CD-ROM are protected. True-type fonts Micros.ttf, Tahoma.ttf, and Tahomabd.ttf are also protected.

You can change the size of the Dllcache folder by typing the following command at a command prompt

sfc /cachesize=xx

where xx represents the maximum size in MB for the Dllcache folder.

For additional information about WFP and other improvements in Windows 2000, refer to the following Microsoft Web site:

http://www.microsoft.com/Windows/server/eval/strategic/relavail.asp

For additional information, click the article numbers below to view the articles in the Microsoft Knowledge Base:

Q222473 Registry Settings for Windows File Protection

Q222193 Description of the Windows 2000 Windows File Protection Feature

Additional query words:

Keywords : kbenv
Version : WINDOWS:2000
Platform : WINDOWS
Issue type : kbprb