If you are not hearing the metronome AND you are also getting a "Database Error" when you open Cakewalk the two issues are probably combined.
The following instructions from SCOOK in response to a Cakewalk Forum thread on "Database Error" fixed the "no metronome" and the "Database Error" problems for me.
"If reboot does not fix it and before reinstalling, the database is reinitialized when repersonalizing SONAR or by renaming/removing the existing database. Open Windows Explorer and paste %appdata%\Cakewalk\Library in the path entry. Rename or remove Library.db in this folder and start SONAR. This will copy the seed database from C:\ProgramData\Cakewalk\Library. Repersonalizing or copying the database will lose any custom category assignments."
Here is the link to that page. SCOOK's response is about 60% down the page. http://forum.cakewalk.com/Database-connection-error-message-m3618978.aspx
