If done correctly yes, but be careful! You may just want to invest in a good eSATA card and an external hard drive enclosure.
Thanks for the reply man...i did it anyways by removing the eSATA to USB adapter which was came by default with the external drive and connecting it with internal power supply and SATA cable...worked like a charm :-)
actually this external drive does not comes with any enclosure. It just contains a USB to eSATA converter adapter which links it through different ports. It can be used internally as well as externally, all you gotta do is connect or disconnect the adapter according to the connection you want.