To be honest, spuds, tried these type of programs before. As well as 'boosters' there are 'optimising' and 'care' programs as well. For me they are a waste of time. By the time you realise you aren't getting any better results you've wasted valuable time. Sometimes they can create problems you can't figure out.
Four programs I use to keep my PC happy are
ATF cleaner; click here
Cleanup!; click here
Regscrubvistaxp; click here
And Auslogics defrag. Don't download the 'booster' program just the basic defragger if you tend to use; click here .
Just my opinion though.