要帮同事调公司的博客，这是基于 .Text 搭的环境，于是我在 VPC 里安装了 VS2003。用惯了 VS2005 + ReSharper，突然回到几年前的 IDE 环境里，颇不适应，于是我想起了 ReSharper，针对 VS2003 的最新版是 2.0.4。

安装到最后时，Command 窗口提示正在招行 InstallUtil.exe，我按照提示信息等了很多个 several minutes，任我按空格、驾车就是没办法，最后不得不 Kill 了这个窗口。ReSharper 提示我安装失败，错误信息是 1722。

反复试了三两遍，装了 VS2003 SP1，问题依旧。最后，搜索到了这个帖子，如法炮制，搞定！

In order for ReSharper installer to work properly, some VS.NET assemblies (like Extensibility) should be in the Global Assembly Cache (GAC). They are normally installed there during VS.NET installation. However, some faulty installers may remove these assemblies from the GAC. So ReSharper installer will be unable to register its own components for Interop and therefore will fail. Workaround is very simple: install necessary assemblies (usually only Extensibility) by running

"[VSInstallDir]\SDK\v1.1\Bin\gacutil.exe" /i "[VSInstallDir]\Common7\IDE\PublicAssemblies\extensibility.dll"

where VSInstallDir is the root VS.NET 2003 installation folder.

我实在是想不明白，为什么 extensibility.dll 这个文件就没被注册到 GAC 呢？以前没有出现过类似问题啊，怪哉。