Is it necessary to install OPS Agent when installing OPS Server on WIN Server?

hi

my question is

i have installed opscenter 7.5 on win server 2003 32 bit ,but its RAM is 2GB ,on the same server where NB 7.5.0.4 is installed.

And also upgraded ops 7.5.0.4

when i log in i am unable to get any data on Ops Center . i have also added the OPS Center server name (same as master server name on OPS CENTER server properties in Netbackup Master server)

i have not installed view builder and Ops Agent .

So will i have to install Ops View and Ops Agent also ?