To keep your PC running like it was brand new. I have 200 GB HD Space on my laptop, and I am running Windows Vista Home Premium...what software will keep it running at maximum performance.....like it was new
Unfortunately it will never stay that way unless you never add/download additional programs. Over a period of time your start up processes increase, the registry grows in size, your antivirus have more files to scan as does your anti-spyware programs. Then there's fragmentation.
Most important is regularly clearing out the crap and CCleaner is good for this, it's very safe to use but their are more aggressive ones out there.
Regularly de-fragment to stop the HD from searching all over the place.
We all have our favourites and the more aggressive ones will flag up more in their scanning but also runs the risk of deleting an important entry. The registry is the heart of your PC and if corrupted will pull down your PC.
I tend to use Easy Cleaner by Toniarts also, again not an aggressive one.
This is why people like to re-install regularly to recover their speed they once had.