cannot save images without saveFileDialog visual basic - vb.net

Question

ive been working on a screenshot program that upload the image automaticly to an FTP server. but i get an error when i try to use:
PictureBox1.Image.Save("C:\test.bmp", System.Drawing.Imaging.ImageFormat.Bmp)
and i always get the Error:
A generic error occurred in the GDI+
ErrorCode: -2147467259
source- System.Drawing
Full ERROR CODE BELOW (vid = at in english):
System.Runtime.InteropServices.ExternalException was unhandled
ErrorCode=-2147467259
Message="Ett allmänt fel uppstod i GDI+."
Source="System.Drawing"
StackTrace:
vid System.Drawing.Image.Save(String filename, ImageCodecInfo encoder, EncoderParameters encoderParams)
vid mostlyTesting.Form1.Timer1_Tick(Object sender, EventArgs e) i C:\Users\emil\AppData\Local\Temporary Projects\mostlyTesting\Form1.vb:rad 22
vid System.Windows.Forms.Timer.OnTick(EventArgs e)
vid System.Windows.Forms.Timer.TimerNativeWindow.WndProc(Message& m)
vid System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
vid System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)
vid System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(Int32 dwComponentID, Int32 reason, Int32 pvLoopData)
vid System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
vid System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
vid Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.OnRun()
vid Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.DoApplicationModel()
vid Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.Run(String[] commandLine)
vid mostlyTesting.My.MyApplication.Main(String[] Args) i 17d14f5c-a337-4978-8281-53493378c1071.vb:rad 81
vid System.AppDomain._nExecuteAssembly(Assembly assembly, String[] args)
vid Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
vid System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
vid System.Threading.ThreadHelper.ThreadStart()
InnerException:

Answer 1

I think what you want is this here
Me.PictureBox1.Image.Save(IO.Path.Combine(My.Computer.FileSystem.SpecialDirectories.Desktop, "TestFile.bmp"))
I hope it helps you. Good luck!
Update:
After I saw Plutonix comment, I tried what he said and It's true, When I try to save the image on C:\ (root folder) It gave me the same error as its giving to you. When I tried with a different path, it worked! The only way is to Run as Administrator and It works for C:\