Thanks Brian,I am new to such processes.
I have Moss 2007 + Project server 2007 environment.To update it with SP3,I have to follow below order
a)Update Environment with WSS3.0 SP3
b)Update 2007 Microsoft Office servers Service Pack 3 (SP3)(I assume it covers both Project server 2007 and MOSS 2007).
Please correct me if I am wrong.Thanks again