why does this give errors on some users, and works fine on others?

[Pouncer]

Open "C:\Windows\system32\newtext.txt" For Append As #1
                    Print #1, "test"
                    Close #1
            
                    If Not File_Exists(GetFile("test.txt")) Then
                        MkDir "C:\folder-test"
                    End If
                    
                    Open GetFile("test.txt") For Append As #1
                    Print #1, "test2"
                    Close #1