Do you need to target versions earlier than Windows 10? If so, you'll have to rule out a Universal Windows Platform app (which might otherwise suit your needs, though you wouldn't be able to use it to write to AppData).

A Windows Presentation Foundation or Windows Forms app targeting .NET 4.0 will get you pretty good compatibility - Windows 8 and above come with it pre-installed* and it's an optional Windows Update for Windows XP/Vista/7. I don't think the XAML learning curve is as steep as some people claim, but it'll still be quicker to hack something together in WinForms over WPF if you haven't used the latter before.

Also check out the Desktop App Converter for Windows 10 - you can now package up a WPF/WinForms/Win32/etc. app into a UWP app for Windows 10 users and pick up some of the benefits that those apps have†.

* But also heed Raymond Chen: https://blogs.msdn.microsoft.com/oldnewthing/20110404-00/?p=... † https://developer.microsoft.com/en-us/windows/bridges/deskto...