CT Eon

I have just recently cleaned my computer using a duster after having not cleaned it for a good 2-3 months and have 2 pcs connected to a billion...Billion modem which I do not remember the serial for. Since reconnecting the PC however after cleaning it out the machine no longer detects my Ethernet cable as being plugged into my network card (a Realtek RTL8168B/8111B Family PCi-E GBE NIC)....I have tried disabling and renabling the network card on vista, disconnecting the cable and reconnecting it where the network card itself lights up as well as removing the card and re-slotting it in before booting on the PC again however the issue continues to exist. It has always worked for the past year or so and so I am baffled as to why it would suddenly stop working and am currently extremely frustrated. Is anyone able to provide assistance at this point in time?