"System Performance is very slow"

Question

Hi..to all

I am working at a private concern as a desktop remote support engr.I am always getting the issue from different user like "System Performance is very slow" for this issue What are the steps need to be done in order to improve system performance.

I am having some steps are givens below
1.deleting unwanted things
2.deleting prefetch
3 deleting temp. files
4 checking RAM size
5. whther application occupying more memory or not?

is this correct methods?anything need to do more for improving system performance?

in our concern we dont allow any other tool..

I want some steps to proceed on this issue.So kindly provide me some ideas...

Thanks in Advance!!!

Noorul Ameen.A