1) can i purchase Agent for application and database with out server ED.
2) or to install any agent do i need to have atleast one server ED.
3) Do server ED include agent for windows, instead of purchasing extra agent for windows license.
for Q1 and Q2, i think you need to have same version of both products to work properly.
Agents and Features Custom Edition
Licensed per Details
Backup Exec Server Backup Exec Server
Included in Bronze,
Silver and Gold
The Backup Exec Server manages the backup environment
(agents/options) and all tape/disk/cloud storage devices
used for backup and recovery. Each Backup Exec
environment requires at least one Backup Exec Server.
Custom edition licensing: each Backup Exec Server license
includes 1 Agent for Windows to protect the local Backup