Hi Saleem,
Not sure about the temp file but Backup Exec should not be creating any tmp file unless you talking about the AOFO advanced open file option tmp file.
If that is the case first you will need to upgrade to Backup Exec 9.1 with SP5 and re-push all the agent.
9.0 is no longer support as 9.1 is EOL shortly.
If AOFO us being used the again upgrade then make an exlusion in you antivirus software to exlude .tmp file.
---cheers
shirmal