win7 x64 sp1,安装VS2012出现如下提示：
“安装无法继续，因为某些必须的组件失败， 安装时发生严重错误”
如下是我取出的部分，日志，太长不能全部列出：
Microsoft.VisualStudio.Text.UI,version="11.0.0.0",publicKeyToken="b03f5f7f11d50a3a",processorArchitecture="MSIL",fileVersion="11.0.50727.1",culture="neutral")
09/23/2012 21:15:58.293 [4768]: Assembly Install: Exiting CAssemblyCache::UninstallAssembly with hr=00000000
09/23/2012 21:15:58.332 [4768]: Assembly Install: Entering CAssemblyCache::UninstallAssembly(0, Microsoft.VisualStudio.Text.UI.Wpf,version="11.0.0.0",publicKeyToken="b03f5f7f11d50a3a",processorArchitecture="MSIL",fileVersion="11.0.50727.1",culture="neutral")
09/23/2012 21:15:58.482 [4768]: Assembly Install: Exiting CAssemblyCache::UninstallAssembly with hr=00000000
09/23/2012 21:15:58.522 [4768]: Assembly Install: Entering CAssemblyCache::UninstallAssembly(0, Microsoft.VisualStudio.Platform.VSEditor,version="11.0.0.0",publicKeyToken="b03f5f7f11d50a3a",processorArchitecture="MSIL",fileVersion="11.0.50727.1",culture="neutral")
09/23/2012 21:15:58.671 [4768]: Assembly Install: Exiting CAssemblyCache::UninstallAssembly with hr=00000000
09/23/2012 21:15:58.711 [4768]: Assembly Install: Entering CAssemblyCache::UninstallAssembly(0, Microsoft.VisualStudio.Language.Intellisense,version="11.0.0.0",publicKeyToken="b03f5f7f11d50a3a",processorArchitecture="MSIL",fileVersion="11.0.50727.1",culture="neutral")
09/23/2012 21:15:58.859 [4768]: Assembly Install: Exiting CAssemblyCache::UninstallAssembly with hr=00000000
09/23/2012 21:15:58.898 [4768]: Assembly Install: Entering CAssemblyCache::UninstallAssembly(0, Microsoft.VisualStudio.Language.StandardClassification,version="11.0.0.0",publicKeyToken="b03f5f7f11d50a3a",processorArchitecture="MSIL",fileVersion="11.0.50727.1",culture="neutral")
09/23/2012 21:15:59.050 [4768]: Assembly Install: Exiting CAssemblyCache::UninstallAssembly with hr=00000000
09/23/2012 21:15:59.088 [4768]: Assembly Install: Entering CAssemblyCache::UninstallAssembly(0, Microsoft.VisualStudio.ExtensibilityHosting,version="11.0.0.0",publicKeyToken="b03f5f7f11d50a3a",processorArchitecture="MSIL",fileVersion="11.0.50727.1",culture="neutral")
09/23/2012 21:15:59.240 [4768]: Assembly Install: Exiting CAssemblyCache::UninstallAssembly with hr=00000000
09/23/2012 21:15:59.279 [4768]: Assembly Install: Entering CAssemblyCache::UninstallAssembly(0, Microsoft.VisualStudio.FileDiscovery,version="11.0.0.0",publicKeyToken="b03f5f7f11d50a3a",processorArchitecture="X86",fileVersion="11.0.50727.1",culture="neutral")
09/23/2012 21:15:59.429 [4768]: Assembly Install: Exiting CAssemblyCache::UninstallAssembly with hr=00000000
09/23/2012 21:15:59.468 [4768]: Assembly Install: Entering CAssemblyCache::UninstallAssembly(0, Microsoft.VisualStudio.Diagnostics.Measurement,version="11.0.0.0",publicKeyToken="b03f5f7f11d50a3a",processorArchitecture="MSIL",fileVersion="11.0.50727.1",culture="neutral")
09/23/2012 21:15:59.616 [4768]: Assembly Install: Exiting CAssemblyCache::UninstallAssembly with hr=00000000
09/23/2012 21:15:59.657 [4768]: Assembly Install: Entering CAssemblyCache::UninstallAssembly(0, Microsoft.VisualStudio.Ultimate.StartPage,version="11.0.0.0",publicKeyToken="b03f5f7f11d50a3a",processorArchitecture="MSIL",fileVersion="11.0.50727.1",culture="neutral")
09/23/2012 21:15:59.807 [4768]: Assembly Install: Exiting CAssemblyCache::UninstallAssembly with hr=00000000
另外，我用collect.exe截取了错误日志。
请求帮助，Thanks.
