Once Windows 2008 R" SP1 installed please follow those steps to setup Backup exec 2010 R3
1. To download your free version of backup exec R3 (if you already have backup exec 2010) go there :
https://www4.symantec.com/Vrt/offer?a_id=933552. Clic on download now (at the bottom)
3. Clic I Agree
4. Identify yourself with your symantec login or create a new account
5. Download Backup Exec 2010 R3 (Full ISO)
6. setup backup exec wihtout removing the previous version that way the licence will be transfered in the new version.
The system state backup should be faster.