There is 2 types of slot that is been used on Win 7 and later motherboards.
PCI and PCIe
PCI
http://en.wikipedia.org/wiki/Conventional_PCI
PCIe
http://en.wikipedia.org/wiki/PCI_Express
If
your slot is a PCIe, pls choose H50113 External
USB modem since PCIe modem is EOL (Phase Out) in 2011 due to no chipset
available.