Process: OSA.EXE (Microsoft Office XP component)
from 
Stardock Forums
Stardock Forums
OSA.EXE - General Information
Name:
OSA.EXE (Microsoft Office XP component)
Publisher
Microsoft Corporation
Product:
Microsoft Office XP
Default location:
%ProgramFiles%\Microsoft Office\Office10\OSA.EXE
OSA.EXE - Description and Recommendation
osa.exe is installed with Microsoft Office Suite. This
process is the startup assistant which improves performance and deals
with some commands. This program is a non-essential process, but should
not be terminated unless suspected to be causing problems.
OSA.EXE - Uninstall Techniques