MSDN详细介绍了如何从注册表中检查它:

To find .NET Framework versions by viewing the registry (.NET Framework 1-4) On the Start menu, choose Run. In the Open box, enter regedit.exe.You must have administrative credentials to run regedit.exe. In the Registry Editor, open the following subkey: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\NET Framework Setup\NDP The installed versions are listed under the NDP subkey. The version number is stored in the Version entry. For the .NET Framework 4 the Version entry is under the Client or Full subkey (under NDP), or under both subkeys. To find .NET Framework versions by viewing the registry (.NET Framework 4.5 and later) On the Start menu, choose Run. In the Open box, enter regedit.exe. You must have administrative credentials to run regedit.exe. In the Registry Editor, open the following subkey: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\NET Framework Setup\NDP\v4\Full Note that the path to the Full subkey includes the subkey Net Framework rather than .NET Framework Check for a DWORD value named Release. The existence of the Release DWORD indicates that the .NET Framework 4.5 or newer has been installed on that computer.

注意:上面快照中被剪切的最后一行在所有其他操作系统版本上为:461310。我尽我最大的努力避免在截屏时信息被剪切，但表格太大了。

这个答案只适用于。net Core !

在您选择的终端中输入dotnet——version将打印出所使用的. net Core SDK的版本。

在这里了解更多关于dotnet命令的信息。

如果打开命令提示符并键入以下两个命令，将列出当前机器上安装的所有框架版本(每个版本都存储在该目录中的单独目录中)。

cd %systemroot%\Microsoft.NET\Framework

dir /A:D

下面是Power Shell脚本，我使用的参考:

https://stackoverflow.com/a/3495491/148657

$Lookup = @{
    378389 = [version]'4.5'
    378675 = [version]'4.5.1'
    378758 = [version]'4.5.1'
    379893 = [version]'4.5.2'
    393295 = [version]'4.6'
    393297 = [version]'4.6'
    394254 = [version]'4.6.1'
    394271 = [version]'4.6.1'
    394802 = [version]'4.6.2'
    394806 = [version]'4.6.2'
    460798 = [version]'4.7'
    460805 = [version]'4.7'
    461308 = [version]'4.7.1'
    461310 = [version]'4.7.1'
    461808 = [version]'4.7.2'
    461814 = [version]'4.7.2'
    528040 = [version]'4.8'
    528049 = [version]'4.8'
}

# For One True framework (latest .NET 4x), change the Where-Oject match 
# to PSChildName -eq "Full":
Get-ChildItem 'HKLM:\SOFTWARE\Microsoft\NET Framework Setup\NDP' -Recurse |
  Get-ItemProperty -name Version, Release -EA 0 |
  Where-Object { $_.PSChildName -match '^(?!S)\p{L}'} |
  Select-Object @{name = ".NET Framework"; expression = {$_.PSChildName}}, 
@{name = "Product"; expression = {$Lookup[$_.Release]}}, 
Version, Release

上面的脚本使用了注册表，并提供了Windows更新号以及安装在机器上的. net Framework。

参考:https://learn.microsoft.com/en-us/dotnet/framework/migration-guide/how-to-determine-which-versions-are-installed # to-find-net-framework-versions-by-querying-the-registry-in-code-net-framework-45-and-later

下面是在两台不同的机器上运行该脚本时的相同结果

已经安装了。net 4.7.2的地方:

未安装。net 4.7.2的地方:

只需键入下面任何一个命令，在第一行中显示最新版本。

1. CSC
2. GACUTIL /l ?
3. CLRVER

如果你安装了Visual Studio，你只能从Visual Studio命令提示符运行这些，或者如果你有。net框架SDK，那么SDK命令提示符。

4. wmic product get description | findstr /C:".NET Framework"
5. dir /b /ad /o-n %systemroot%\Microsoft.NET\Framework\v?.*

最后一个命令(5)将列出所有已安装的。net版本(除了4.5)，最新版本优先。您需要运行第4个命令来查看是否安装了. net 4.5。

PowerShell命令提示符中的另外三个选项如下所示。

6.   [environment]::Version
7.   $PSVersionTable.CLRVersion
8.   gci 'HKLM:\SOFTWARE\Microsoft\NET Framework Setup\NDP' -recurse | gp -name Version,Release -EA 0 |
     where { $_.PSChildName -match '^(?!S)\p{L}'} | select PSChildName, Version, Release

最后一个命令(8)将给出所有版本，包括。net 4.5。

试试Scott Hanselman的. net Checker。