Help , can not open file attachment

Dear all,

im using endnote X1, word 2007 and windows vista

i can attach file on my reference using endnotex1, but i can not open the file that i’ve attached. It said

This URL (//D:\Documents\Endnote libary\data\pdf\123.pdf) could not be launched

even i tried other file on my previous libary, i cannot open it also.

can anybody help me? 

Thank you