I've turned on my PC 1 hour ago and it told me: "Hello .... you Windows has been updated with new features .." and so on. That's ok.
Then I compiled an app on Delphi XE3: that's ok too.
Then another one in Delphi 2007, and the following message appeared:
Unable to load project xxxxx The imported project "C:\Windows\Microsoft.NET\Framework\v2.0.50727\Borland.Delphi.Targets" was not found.
I just had this problem weeks ago and solved with this answer on Stackoverflow: Delphi 2007 x Windows 10 - Error on opening project
But it seems this automatic Windows upgade had now deleted my files: I do not find it in any c:\Windows subfolder.