Express 7.18.0.0 on Windows 7 Professional

But, how is it possible finding these files on C after having already uninstalled Express?

The older version that works is 7.17.3 but it's impossible to be downloaded via Garmin website since the 7.18 is now on!

I suggest all we Windows7 users wait for an official announcement from Garmin tech support.

It might be worthwhile to run the Microsoft .NET framework repair tool.  You can get it at .NET repair tool 

Another user posted a potential fix and some people reported that it worked.  Go to https://forums.garmin.com/apps-software/mac-windows-software... then scroll down to the input by LpDevRun. The first line reads "Possible fix for 7.18.0.0 version on Win7 Pro x64."

One thing about the modification of a file, I suggest you copy and paste as needed, and then check carefully for the proper content.

Just downloaded Garmin Express 7.18.1.0, it crashed with Win 7 with the same symptoms as described in initial post. 

Version 7.18.1.0, produce the same error, System.AccessViolationException

Exception workaround with   <legacyCorruptedStateExceptionsPolicy enabled="true" /> is fixing an error.

Error source: .NET Runtime

More info about error:

System.AccessViolationException
   in Windows.Win32.PInvoke.DeviceIoControl(Windows.Win32.Foundation.HANDLE, UInt32, Void*, UInt32, Void*, UInt32, UInt32*, System.Threading.NativeOverlapped*)
   in Windows.Win32.PInvoke.DeviceIoControl(System.Runtime.InteropServices.SafeHandle, UInt32, Void*, UInt32, Void*, UInt32, UInt32*, System.Threading.NativeOverlapped*)
   in DeviceManagement.Detection.WinDeviceWatcher.GetDeviceNumber(System.String)
   in DeviceManagement.Detection.WinDeviceWatcher.HandleDeviceArrival(System.String, System.Guid, System.DateTime)
   in DeviceManagement.Detection.WinDeviceWatcher+<StartAsync>d__16.MoveNext()
   in System.Runtime.CompilerServices.AsyncTaskMethodBuilder.Start[[DeviceManagement.Detection.WinDeviceWatcher+<StartAsync>d__16, DeviceManagement, Version=6.1.0.0, Culture=neutral, PublicKeyToken=null]](<StartAsync>d__16 ByRef)
   in DeviceManagement.Detection.WinDeviceWatcher.StartAsync()
   in DeviceManagement.DeviceService+<StartAsync>d__18.MoveNext()
   in System.Runtime.CompilerServices.AsyncMethodBuilderCore+MoveNextRunner.InvokeMoveNext(System.Object)
   in System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)
   in System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)
   in System.Runtime.CompilerServices.AsyncMethodBuilderCore+MoveNextRunner.Run()
   in System.Runtime.CompilerServices.YieldAwaitable+YieldAwaiter.RunAction(System.Object)
   in System.Windows.Threading.ExceptionWrapper.InternalRealCall(System.Delegate, System.Object, Int32)
   in System.Windows.Threading.ExceptionWrapper.TryCatchWhen(System.Object, System.Delegate, System.Object, Int32, System.Delegate)
   in System.Windows.Threading.DispatcherOperation.InvokeImpl()
   in System.Windows.Threading.DispatcherOperation.InvokeInSecurityContext(System.Object)
   in MS.Internal.CulturePreservingExecutionContext.CallbackWrapper(System.Object)
   in System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)

me to

Windows 7 uses only. Please rollback Garmin Express to v7.17.3 through this link:

-  Windows 7 - Garmin Express v7.17.3

Please note: the Garmin Express system requirements are now Windows 10 or newer. You must continue to use the v7.17.3 Garmin Express if you continue to use Windows 7.