Carbon Copy (software) Carbon Copy was an early remote control and file transfer software for DOS and Windows published by Microcom. It allowed remote access to a computer via dial-up modem connection.
A viral infection (the common cold) is the most common cause of a stuffy and/or runny nose, but allergies, influenza, and sinus infections also may cause these symptoms. Less commonly, anatomical obstructions (e.g. a deviated nasal septum, foreign bodies) may lead to nasal congestion.
When an individual has allergies it causes excess mucus to be produced in the nasal passages and sinus cavities. This excess of mucus cannot drain correctly and effectively out the nasal passages at times and as a result, the mucus containing foreign particles flows down the back of the throat, causing post nasal drip.