Nemam jak vyzkouset, ale pisou, ze aby to fungovalo, musi se prvne updatovat BIOS na verzi 2.6.6 (latest Legacy BIOS revision 2.6.6) a pak:
745 works fine with windows 7. You do need chipset drivers and Vista Audio drivers.
http://downloads.dell.com/published/pages/optiplex-745.html