Thank of everybody help!
I judge the MD hard to connect PC no software issue. the mostly probable is mainboard fault.
I have clear the old versions SS before new versions installing in window XP system.(delete Include share file, regedit and so on). And the MD still cannot connect PC.
Future,I will try to disassembly MD. Please kindly give any suggestion if anybody has been disassembled the N1O. ( i will major to inspection which circuit).
Thanks!