vb问题？？
Public Class Form2
Inherits System.Windows.Forms.Form
Dim commentary(4) As String
Dim Filename(4) As String
Dim Currentphoto As Integer

Private Sub loadphoto()
PictureBox1.Image = Image.FromFile(Filename(Currentphoto))
//在2005下编译上边的那句那错了？
Label1.Text = commentary(Currentphoto)
End Sub

Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button4.Click
Currentphoto = 4
loadphoto()
End Sub
Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
Currentphoto += 1
If Currentphoto > 4 Then Currentphoto = 1
loadphoto()
End Sub
Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
Currentphoto -= 1
If Currentphoto < 1 Then Currentphoto = 4
loadphoto()
End Sub
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Currentphoto = 1
loadphoto()
End Sub
Private Sub Form2_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
commentary(1) = "nihao1 "
commentary(2) = "nihao2 "
commentary(3) = "nihao3 "
commentary(4) = "nihao4 "
Filename(1) = Application.StartupPath & "E:\IMG_0674.JPG "
Filename(2) = Application.StartupPath & "E:\IMG_0675.JPG "
Filename(3) = Application.StartupPath & "E:\IMG_0676.JPG "

Filename(4) = Application.StartupPath & "E:\IMG_0677.JPG "
Currentphoto = 1
Call loadphoto()
End Sub
End Class

[解决办法]
Filename(1) = Application.StartupPath & "E:\IMG_0674.JPG "

Application.StartupPath 是您EXE文件的存放路径，您在后面又加上一个绝对路径，这个可能就不对了，所以Image.FileFrom方法就不能取道正确的文件了。
[解决办法]
Application.StartupPath

就是您正在写的这个程序的EXE文件的存放路径。
[解决办法]
如果您的图片是 "E:\IMG_0674.JPG "，那么把Application.StartupPath去掉就好了。