[c#] File.Move Does Not Work - File Already Exists

You need to move it to another file (rather than a folder), this can also be used to rename.

Move:

File.Move(@"c:\test\SomeFile.txt", @"c:\test\Test\SomeFile.txt");

Rename:

File.Move(@"c:\test\SomeFile.txt", @"c:\test\SomeFile2.txt");

The reason it says "File already exists" in your example, is because C:\test\Test tries to create a file Test without an extension, but cannot do so as a folder already exists with the same name.