I recently bought a D-LINK "DES-100D" switch. In which i connected two computers and a internet port that is coming from a ADSL router. The network icon in the taskbar shows connection continuously connects and disconnecting. I have this problem on both PC. It actually happens when i connect the ADSL port in switch, otherwise the connection b/w the PC's work with no problem.
Can any one help me of this continuously disconnecting of both PC's from the n/w.

any1 pls.

what are your ip settings?
is the adsl modem a router as well?
is it DES-1008D
i take it that you are using the port/cable that comes from the modem and usually would go to the pc to connect it to the switch and then connect the pc's to the switch as well. correct?

Yes it is DES-1008D. The modem is not that type of router, it just a ADSL router.
Router ip address is 192.168.1.1
My pc ip address is 192.168.1.2
Other pc has ip 192.168.1.3

DNS are also configured.

Well all ports are plugged-in in the switch, i.e PC1,PC2,Router modem. When the Pc is on, it first show the connectivity for few seconds and the popup message appears..."A cable is unplugged".