What other drive? Do you mean a partition on C? or another hard drive? Floppies and CD drives can be scanned by clicking the appropriate button on the interface.
If you open the Avast GUI (Interface) and click the Local Drive button, Avast will scan the Local drive . That drive being normally "C". If that doesn't work, then I would go to files and folders button. Put an X next to the drive you want scanned and Avast will scan all folders and files within that drive. Same thing but a different approach.
