The .NET Framework 2.0 SP1 installation fails on a computer that has the .NET Framework 2.0 installed and that is running Windows XP, Windows Server 2003, or Windows 2000

When you try to install the Microsoft .NET Framework 2.0 Service Pack 1 (SP1) on a computer that has the .NET Framework 2.0 installed and that is running Windows XP, Windows Server 2003, or Windows 2000, the .NET Framework 2.0 SP1 installation fails.

This problem occurs because Windows Installer must load the cached installation database and all updates when Windows Installer performs any maintenance installations, such as uninstallations. If packages for those updates do not exist in the Windows Installer cache, Windows Installer tries to find the updates from earlier source directories.

The .NET Framework 2.0 SP1 is a major upgrade that uninstalls the earlier version of the .NET Framework 2.0. If Windows Installer cannot find the packages for the earlier installed updates during the uninstall operation, the installation fails with an error message.

If an incomplete rollback occurs, this failure to install may also cause applications that use the .NET Framework to fail.

This problem may occur for one of the following two reasons.

The Windows Installer cache is missing necessary files

The Windows Installer cache is critical for repairing, for updating, and for uninstalling products. Therefore, you should not remove or modify the contents of the cache. If you change the contents of the cache, you may be prompted for a source when you try to update or to repair Windows Installer-based products.

Sometimes a Windows Installer Patch (.msp) file that Windows Installer expects to find in the cache may not exist. The following are two common reasons why the .msp file may be missing:

• You run a tool that finds and deletes large files or rarely used files on your disk.
• The owner of the %windir%\Installer directory changes from SYSTEM or from Administrators.

If this issue occurs, you see the following in the Windows Installer log for the failing installation:

MSI (s) (D0:B0) [19:05:57:843]: Couldn't find local patch 'C:\WINDOWS\Installer\a4784a.msp'. Looking for it at its source. MSI (s) (D0:B0) [19:05:57:843]: Resolving Patch source.

You can use the Microsoft .NET Framework 2.0 Registration Correction Tool to resolve this issue when it occurs when you install the .NET Framework 2.0 SP1. The tool fixes this issue by deleting all hotfix or update registrations that are specific to this update so that maintenance installations do not try to load the specific .msp file.

You can also try to fix this issue by rebuilding the installer cache. You can typically find the Knowledge Base number for the hotfix or for the update in the lines that follow "Resolving Patch source," as shown in the following example:

MSI (s) (D0:B0) [19:05:57:859]: SOURCEMGMT: Source is invalid due to missing/inaccessible package.
MSI (s) (D0:B0) [19:05:57:859]: Note: 1: 1706 2: -2147483647 3: NDP20-KB917283-X86.msp

To fix the Windows Installer Cache for this example, follow these steps:

1. Visit the following Microsoft Web site:
   http://support.microsoft.com/kb/917283
   Note You can replace the Knowledge Base article number in the URL with the Knowledge Base article number of the hotfix or the update for which you want to fix the Windows Installer cache.
2. Download the update.
3. Extract the .msp file that is inside the hotfix or the update by using the /x command-line switch or the /extract command-line switch.
4. Copy the extracted .msp file to the location for the missing file. In this example, the location is %windir%\Installer\a4784a.msp.

The hotfix registration or the update registration is corrupted

After a hotfix or an update is installed on a Windows Installer-based product, the hotfix registration or the update registration may become corrupted. This problem can occur because of third-party registry cleaner utilities that remove certain registry keys. These keys include the keys that are meant for internal use by Windows Installer. In this case, the "Resolving Patch source" message in the log reads as follows:

MSI (s) (CC:5C) [03:02:56:181]: Couldn't find local patch ''. Looking for it at its source.
MSI (s) (CC:5C) [03:02:56:181]: Resolving Patch source.

Note The location of the hotfix or the update is missing in the log message because of the missing hotfix or upate registration information. In this case, a hotfix or an update is still registered to a product. However, location information for the hotfix or update is missing. Although the file may exist, Windows Installer does not know the path of the file that Windows Installer needs in order to load.

You can use the Microsoft .NET Framework 2.0 Registration Correction Tool to resolve this issue when it occurs when you install the .NET Framework 2.0 SP1. The tool fixes this issue by deleting all hotfix or update registration that is specific to this service pack so that maintenance installations do not try to load the hotfix or the update package.

If you cannot successfully install the .NET Framework 2.0 SP1 and find the "Resolving Patch source" text in the installation log file as described in the �Cause� section, you can download the Microsoft .NET Framework 2.0 Registration Correction Tool to resolve this issue.

Microsoft .NET Framework 2.0 Registration Correction Tool

The Microsoft .NET Framework 2.0 Registration Correction Tool resolves both of the issues that the �Cause� section describes.

The following file is available for download from the Microsoft Download Center:
Download the Microsoft .NET Framework 2.0 Registration Correction Tool package now.

The Microsoft Download Center has one version of the tool for each processor architecture that the .NET Framework 2.0 supports (x86, x64, and IA-64). Most customers run a 32-bit version of the operating system. Therefore, these customers need to download and to install the x86 version of the tool.

Administrators may also use this utility in scripts by passing either the /q command-line switch or the /quiet command-line switch. In this way, you can run the application in silent mode without using a user interface and without using block scripts.

The tool writes a running log under the %TEMP%\dd_clwireg.txt folder. You can view this log for more information about what the tool is doing.

Notes

• The Microsoft .NET Framework 2.0 Registration Correction Tool is not designed to be used with any version of the .NET Framework other than the .NET Framework 2.0.
• You must be an administrator to run this utility.

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

How to prevent the issues that this article describes

Make sure that you do not remove files that are located directly in the %WINDIR%\Installer directory. Additionally, make sure that disk space reclamation utilities that free up space by deleting large files or rarely used files do not remove the files under this directory.

The Windows Installer CleanUp Utility uses the Msizap.exe file. This utility is included with the Windows Software Development Kit (SDK). The utility can delete some files or all files in the Installer cache. However, you should only use this tool as a last resort. Make sure that you carefully read all information and warnings about the utility before you use the utility. It is always best to uninstall a product, a hotfix, or an update by using Windows Installer through one of the following:

• The Add or Remove Programs utility in Windows 2000, in Windows XP, or in Windows Server 2003
• The Software Explorer in Windows Vista or in newer versions of the Windows operating system
• The Msiexec.exe file on the command line (if the product does not provide its own uninstaller)

Note This article does not describe any issue that affects the .NET Framework 2.0 on Vista and on later operating systems.

For more information about the Windows Installer CleanUp Utility, click the following article number to view the article in the Microsoft Knowledge Base: