[newbie] How to manually enable HD optimisations after install

[Wise, William M.]

Just wondering how I would manually enable HD optimisations after
installing and specifying during the install that they should be turned
off.  

I was trying to figure out a problem I was having (turned out to be
automount) and thought reinstalling with optimisations might do the
trick.  How can I turn them on now that I know that they weren't the
source of my problem.  

Thanks in advance for any help you can provide,
Will