Having a set of the .NET Frameworks that works correctly is important for all Windows users and developers are no exception. Through the course of development, it is easy to accidentally overwrite needed files. In an effort to minimize troubleshooting, Microsoft provides the .NET Framework Repair Tool. This tool provides the ability to scan a Windows system for errors with any of the .NET Framework packages that are supposed to be installed.
The program may be executed via the command line or through a graphical wizard. Command line switches are available which allow the tool to be run unattended and to enable proper .NET packages to be located on a network share (versus requiring Internet access). There is also an option to disable the default behavior of sending a diagnostic log file to Microsoft after the tool has been executed.
The typical operation of the utility takes the following steps:
- Scan the machine for the known errors with .NET Framework installations and if found, provide a list to the user for ereview
- Take any of the following corrective measures:
- Ensuring Windows Installer service is properly operational
- Reset discretionary access control lists on system folders
- Verify and correct update registration
- If the actions in step 2 have not been successful in correcting the issue, provide user with an option to perform a full repair of the installed .NET Frameworks.
- Optionally send a CAB file containing system logs for transmission to Microsoft.
In a trial run on this author's machine, the program's operation took approximately 20 minutes. When completed, a cab file was left in %TEMP% directory which contained all of the log files from my user directory's AppData. The cab also included registry dump files for HKCR and HKLM (HKEY_LOCAL_MACHINE).
Full details on the program’s operation are available in a blog post by The .NET Fundamentals Team and in its corresponding KB article. The latest version, V1.3, includes support for all .NET Frameworks through 4.6.1. It supports operation on Windows operating systems through Windows 7 Service Pack 1 and Windows Server 2008 R2 Service Pack 1.