Copying CD and DVDs in Windows 7 requires a third party utility. You will need a blank CD or DVD (whichever you are copying which could be in R or RW format).
In Windows XP you could choose in the right select menu for the CD/DVD and copy the CD or DVD. That disappeared in Windows 7. I am disappointed in Microsoft removing this as it was a useful way to back up your CD/DVDs and backing up your data is important
The programs I have used with Windows 7 to copy CD and DVDs are ISO Recorder and CDBurnerXP. Both work in Windows 7 (CDBurnerXP was originally written for XP but is fine when used in Windows 7). Both are free utilities on the Internet for personal use.
CDBurnerXP has a friendlier menu system to it to copy/duplicate the CDs and DVDs. ISO Recorder adds an option in the right click menu when choosing the CD that is labeled Copy CD to CD and then pops up a screen asking what you are copying and leads you through.
CDBurnerXP is available from http://cdburnerxp.se/en/home
ISO Recorder is available at http://alexfeinman.com/isorecorder.htm You want the recorder program not the writer program which is a command line program and more advanced.