问题
I just installed VS 2012 Ultimate RTM on Windows 8 Pro RTM and tried to open a solution containing several projects (class libraries and WinForms) targeting .NET 4.0. When the solution is loaded, VS prompts that .NET 4.0 isn't supported. It gives me the chance to update my projects to 4.5 (and promises that I could change the target later) or install a "Multi targeting pack" for 4.0 from this page. I decided to update my projects to 4.5 because I had no luck installing the offered Multi targeting pack (errors see below). Unfortunately, VS does not show 4.0 as a target by default (when changing the target for an updated project), but redirects me to the page where I can download the Multi targeting pack. So far so good, but I wasn't able to install any of the offered downloads (neither runtime nor targeting pack) again. The error message says in case of .NET Framework 4.0.3 Targeting Pack:
Setup has detected that this computer does not meet the requirements to install this software. The following blocking issues must be resolved before you can install KB2600213 software package.
Installation Requirements: Microsoft .NET Framework 4 Multi-Targeting Pack was not found. Please repair your installation for Microsoft Visual Studio 2010 in order to get this update.
Strange enough since I have no VS2010 installed.
.NET Framework 4.0.3 Runtime Installation stops with the following error:
KB2600211 does not apply, or is blocked by another condition on your computer.
I've checked that .NET 4.0 is installed (using the .NET Installation verification tool), I've tried to repair VS2012 but nothing let me target .NET 4 and the Event log does not contain any related reports. Any suggestions or hints (besides going back to Win7/VS2010)?
回答1:
I'm honestly not sure what's going on. I have VS 2012 Ultimate RTM and all versions of .NET are supported.
I'm almost positive I never installed any .NET frameworks manually, though I did install Visual Studio 2010 Express for Windows Phone from http://create.msdn.com.
来源：https://stackoverflow.com/questions/12482746/targeting-net-4-0-in-vs-2012-on-windows-8