copy and paste a range of cells to the left

Hi all, I am new to writing up code in VBA. i am trying to copy cells on a range and paste them to the left into colums A to D. the maro runs but it get rid every second existing raw. This is what I am doing (see the picture), and the code is:

Sub CopyPaste()

Dim I As Long, LastLine As Long
Dim R As Integer

Sheets(2).Activate
LastLine = Cells(Rows.Count, "A").End(xlUp).Row

R = 0
For I = R + 2 To LastLine
Sheets(2).Range("G" & I & ":J" & I).Copy
Range("A" & I & ":D" & I).PasteSpecial
R = R + 2
Next

MsgBox "Done"
End Sub

I would appreciate if someone can can point me in the right direction, thanks heaos!