.NET Framework无法重新安装

今天在客户单位要求在原来的IIS服务器上重新安装DotnetV2.0,不过卸载后直接安装提示错误:

产品: Microsoft .NET Framework 2.0 — Setup cannot continue because this version of the .NET Framework is incompatible with a previously installed one.  For more information, see http://support.microsoft.com/support/kb/articles/q312/5/00.asp