System: E machine T6412 with 450 psu

nvidia geforce 9500 GT card still not showing in "display adaptor"

AMD Athlon 64 - 3400+ 2.5 GB ram

I had an 8500 Gt that was getting flakey & I installed the 9500GT graphic card and a 450 psu both of which were working on another machine. i don't think the card needs auxiliary power and I tryied installing it twice in the pci-e slot but i don't get any sign of the card being in the system even though I have a monitor working through the card port & not the MB vga.

Any suggestions ?? thanks