Tech Tip: Move the WFP cache folder/Troubleshoot DNS issues in Win2K

Learn how to move the WFP cache folder and troubleshoot DNS issues.

Windows 2000 Professional: Move the Windows File Protection cache folder

Windows File Protection (WFP) helps keep programs from replacing system files with other, possibly older, versions. WFP allows only certain applications to replace system files.

These applications include service packs and hot fixes installed with Update.exe, hot fixes installed with Hotfix.exe, operating system upgrades with Winnt32.exe, and Windows Update. The Windows Installer also works through WFP to replace files as needed when installing an application.

WFP maintains a cache folder where it stores a copy of the correct version of each protected file. When a change occurs in a protected folder, Windows checks the version of the file in the protected folder against the version in the cache. If the files are different, Windows copies the cached version into the folder.

The cache folder's default location is %systemroot%\System32. However, this folder can contain a large number of files, so you may want to move the cache folder to another drive, which you can accomplish with a registry edit.

Follow these steps:

  1. Open the Registry Editor (Regedt32.exe).
  2. Navigate to HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Winlogon.
  3. Add or modify the REG_EXPAND_SZ value SFCDllCacheDir to point to the local drive and folder where you want to move the cache.
  4. Close the Registry Editor and restart the computer for the change to take effect.

If the registry key HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows NT\Windows File Protection exists, Windows copies the settings in this key to the Winlogon key at startup. Therefore, this key has precedence. If it exists, you must modify the SFCDllCacheDir value in that key.

However, configuring the cache registry setting doesn't cause Windows to magically copy the files to the new location. Instead, you need to initiate an SFC scan.

Open a command prompt and enter SFC /SCANNOW. Windows will then begin copying the files to the new location. Windows may prompt you to insert the Windows 2000 Professional CD.

Note: Editing the registry is risky, so be sure you have a verified backup before making any changes.

Windows 2000 Server: Troubleshoot DNS issues

When setting up or troubleshooting a DNS server, you have a few local resources at your disposal. One is the DNS console, which you can use to create forward and reverse lookup zones, create DNS records, and manage other DNS service properties. However, the DNS console doesn't provide any testing features.

Another tool you can use locally is Nslookup, which you can launch from a command prompt. With Nslookup, you can view information about the DNS server, query for DNS records, list all records of a specific type, and more.

In many situations, it's also helpful to be able to perform testing on your DNS servers from an external location. For example, you might need to verify that you've properly configured the server for reverse DNS lookups on your mail server and that it's responding properly.

When working with DNS, check out these two Web sites: and These sites offer several tests you can use to quickly test forward and reverse lookups and perform other DNS actions. You'll also find a wealth of other query tools.