Hello,
When you will be installing BEWS 10.0 you will get an option to create a new MSDE instance or to use an existing SQL instance.
Please select the option to create a new MSDE instance this will not affect the existing MSDE instance.
Additional information:
http://support.veritas.com/docs/269793
Additional Information :
For information on the recent VERITAS Backup Exec security vulnerabilities, including links to the downloads for the necessary hotfixes, please refer to the following document:
Patch summary for Security Advisories VX05-001, VX05-002, VX05-003, VX05-005, VX05-006, VX05-007
http://seer.support.veritas.com/docs/277429.htm
NOTE : If we do not receive your reply within two business days, this post would be marked "assumed answered" and would be moved to "answered questions" pool.
Thanks,