Selects are slow and unnescsaary. The following code will be far faster:
Sub CopyRowsAcross()
Dim i As Integer
Dim ws1 As Worksheet: Set ws1 = ThisWorkbook.Sheets("Sheet1")
Dim ws2 As Worksheet: Set ws2 = ThisWorkbook.Sheets("Sheet2")
For i = 2 To ws1.Range("B65536").End(xlUp).Row
If ws1.Cells(i, 2) = "Your Critera" Then ws1.Rows(i).Copy ws2.Rows(ws2.Cells(ws2.Rows.Count, 2).End(xlUp).Row + 1)
Next i
End Sub