Hello,
You will need to upgrade to 10d as 10.0 does not support 64 bit OS. After that install hotfix 1.
Note: the upgrade from 10.0 to 10d is a free upgrade.
Refer to the following links:
10d install files:http://support.veritas.com/docs/279332
10d (10.1.5629) Hotfix 1 - Extended 64-bit (x64) Remote Agent for Windows Servers (RAWS) (Adds support for remote computers running 64-bit extended chipset Windows operating systems)
http://support.veritas.com/docs/280701
Then install the remote agent.