We have these plus a load more but with less of them, this list covers 90%. They are all Windows 7, both x86 and x64
HP Compaq dc7900 Small Form Factor
HP EliteDesk 800 G1 SFF
HP Compaq 8200 Elite SFF PC
HP Z420 Workstation
HP Compaq 8000 Elite SFF PC
HP Compaq Elite 8300 SFF
HP EliteBook 8470p
HP Compaq 6730b
HP Z400 Workstation
HP ProBook 6560b
HP ProBook 6570b
HP xw4600 Workstation
VMware Virtual Platform
HP EliteBook 840 G1
HP ProBook 6550b
HP Z820 Workstation
HP EliteBook 820 G1
HP Z800 Workstation