4^th Gen:

 HP 800G1 /i5 4^th gen /4GB/250-320Gb/DVD or better/W7P COA - qty 84 ( SFF-79, Tower-5)

HP 600G1 /i5 4^th gen /4GB/250-320Gb/DVD or better/W7P COA - qty 22 ( SFF-18, Tower-4)

3rd Gen: 

 HP 8300 /i5 3rd gen/4GB/250-320Gb/DVD or better/W7P COA - qty 45 ( SFF-10, Tower-21, FF-14)

 HP 6300 /i5 3rd gen/4GB/250-320Gb/DVD or better/W7P COA - qty 35 ( SFF-31, Tower-6)

HP 8300 /i3 3rd gen/4GB/250-320Gb/DVD or better/W7P COA - qty 55 ( SFF-27, FF-28,)

HP 6300 /i3 3rd gen/4GB/250-320Gb/DVD or better/W7P COA - qty 70 ( SFF-70, )

2nd Gen: 

HP 8200 /i5 2nd gen/4GB/250-320Gb/DVD or better/W7P COA - qty 107(  Tower-20, FF - 87)

HP 6200 /i5 2nd gen/4GB/250-320Gb/DVD or better/W7P COA - qty 242 ( SFF-167, Tower-75,)

 HP 8200 /i3 2nd gen/4GB/250-320Gb/DVD or better/W7P COA - qty 75(  SFF-24,Tower-51)

 1st gen:

HP 8100 /i5 ist gen/4GB/250-320Gb/DVD or better/W7P COA - qty 94 ( SFF-62, Tower-32)

HP 8100 /i3 ist gen/4GB/250-320Gb/DVD or better/W7P COA - qty 50 ( SFF-3, Tower-47)

All tested working