This article was previously published under Q306160
You may need to repair your installation of the .NET Framework if you upgrade your operating system or if the current installation of the .NET Framework becomes corrupted. This article describes how to do so.
Steps to repair the .NET Framework installation
Obtain the original installation source. For example, if you installed the .NET Framework from a CD-ROM or from a DVD, insert that disc. If you downloaded the .NET Framework , download the .NET Framework again. Make sure that you click save to disk. If you installed the .NET Framework from a network share, reconnect to that share.
Click Start, click Run, type the following command, and then click OK: