For some reason it seems that ampersands are not working like they should when I attempt to use them in shell commands in VB. When I attempt to link two commands together on the
Deleted my other answer, found a simpler way to do this.
This is what you want...
Shell("cmd.exe /c cd C:\ & adb shell monkey -p com.android.system -v 1", AppWinStyle.Hide)
Inserting it into your original code...
Shell("cmd.exe /c cd " & TextBox2.Text.ToString & " & adb -s " & TextBox15.Text.ToString & " shell monkey -p " & TextBox1.Text.ToString & " -v 1", AppWinStyle.Hide)
I tested the first example and it seemed to work.