Hi,
If you check the specs page of the PC at http://www1.us.dell.com/content/products/productdetails.aspx/dimen_4700c?c=us&cs=19&l=en&s=dhs&~tab=specstab#tabtop , it says that they only have PCIe slots and the National Instruments card you mentionned is not PCIe compatible.
The dimensions of the PCI-6036E are 17.5 by 10.6 cm or 6.9 by 4.2 in. You can use these dimensions to ask Dell if it would fit in their machine once you find one that would work with the PCI-6036E.
Hope this helps.
Serges L.