The evaluation version of LabVIEW does not have any features disabled due to the evaluation license.
It sounds like you are in the block diagram - in which case you will only be able to access the functions palette. If you switch to the front panel (by either selecting Window»Show Front Panel or pressing Ctrl+E) you should then be able to access the controls palette.
Have fun getting started with LabVIEW!
Simon H Applications Engineer National Instruments
Hey Simon, I tried to activate the control palette by pressing Ctrl+E as well as Window>>Show front panel. However, the control palette is still grayed out. I cannot use it for further computation Also, I am using the 45days evaluation copy. Requesting you to kindly assist. Regards, Pranav.