Comparing 2 lists

no - thats not quite correct - it would copy all the rows
try this

for each row in sheet2
for each row in sheet 1
if (Sheet2: thisrow:cells1-7 exactly matches Sheet1:this row: cols 1:7)
mark as found and exit loop
else
mark as not found
end if
next row sheet 1
if not found copy sheeet2:thisrow to sheet3
next row sheet2