In an effort to enhance my hp 1240t I have purchased an Ausus Gt 630 graphic card and inserted it into my PCIe 16 slot on my Pegatron 2AD5 motherboard powered by a 300 watt psu.  The motherboard has integrated graphics.  I have checked the bios settings as well as ensuring there are no jumpers on the board to disable the integrated graphics but have not had any success in firing up my new Asus card.  From my reading, the integrated graphics are supposed to automatically disable once the PCIe slot is populated.  

SiSofteware Sandra lite is unable to detect the card and Windows 8.1 doesn't see it either.  If I disable the integrated graphics card in windows I am concerned that I'll have nothing upon rebooting.

Either my new card is faulty or I suspect my 300 watt psu may be inadequate.  The card is rated at 75 watts with no fan.  I am not a gamer and don't have large power requirements (i7 2600 chip) and before purchase I used an online power calculator that indicated everything should work.

Does anyone have experience with this sort of thing, specifically if a card is not powered adequately, should it simply not boot?  I would have thought it should operate and the psu get a bit upset if the draw off is too great.

Any help is appreciated before I open my wallet again and purchase a new PSU or return the video card