When you try to install the BCM you may get this error:

“Error 2835: Setup failed to configure the server, refer to the server error log and setup log for more information.”
or
“Setup has detected existing data/log files. Please make sure to delete/move the files before re-running setup”

This error occours, because you have tried to install the BCM before, and there are some entries in
C:\Program Files\Microsoft SQL Server\MSSQL$MICROSOFTBCM\Data
To solve the problem follow the next steps:
Rename the file that is in the Data folder to file_name.old. To do so:

Locate the C:\Program Files\Microsoft SQL Server\MSSQL$MICROSOFTBCM\Data\ folder.
Right-click any files that are in the
C:\Program Files\Microsoft SQL Server\MSSQL$MICROSOFTBCM\Data\ folder, and then click Rename
Change the file name extension of the file to .old.
Try to install the Business Contact Manager add-in for Outlook 2003.

Rename the Data folder. To do so:
Locate the :\Program Files\Microsoft SQL Server\MSSQL$MICROSOFTBCM\ folder.
Right-click the Data folder, and then click Rename .
Rename the folder to Data-old.
Try to install the Business Contact Manager add-in for Outlook 2003.

Rename the MSSQL$MICROSOFTBCM folder. To do so:
Locate the C:\Program Files\Microsoft SQL Server\ folder.
Right-click the MSSQL$MICROSOFTBCM folder, and then click Rename
Rename the folder to MSSQL$MICROSOFTBCM-old.
Try to install the Business Contact Manager add-in for Outlook 2003