Ahhh, at 5 yrs old most computers are getting kind of outdated.
Unless it's had some upgrades over the years?
do you know your cpu speed & amount of ram?

our computers are home built, and I usually end up rebuilding them about every 4 yrs- or at least a new mother board and CPU & Ram.
the hard drive might get replaced more often if needed
and I've upgraded to the R/W DVD/CD

- hope fully cleaning out extra stuff that gets accumulated over the years will help keep your system going longer for you.
But it would be good to have someone knowledgeable to help you with the registry cleaning if someone is nearby.

But I did run 2 different cleaners on my system last week.
Just used the settings they came with - didn't change anything- and had no problems.