How to change unity performance, and run it in 4 GB RAM ?

Hi my name is mohamed and i’am Game level designer . I downloaded unity 4 and it’s very slow in work Although I have core i5 processor and graphics card 8 GB RAM it works in 10% from the memory and I have 60% not use.
Thanks ,
best regards

Esselam.

what you mean by slow? .does it run slow during runtime or in the development view?

Ur computers specs r high enough 2 meet all da requirements to run unity fast