Less Hard Drive Clutter
With the advent of massive amounts of hard drive storage space now available at such low costs, a user can almost install programs and create documents, without the worry of ever running out of drive space.

A massive external hard drive by Buffalo.
However, this can be a problem for several reasons.
Performance - When a drive stores information, it's stored in blocks of data. These blocks or sectors of data must be read sequentially when executing a program or opening a document. When you clutter the hard drive with unnecessary information, the data is very fragmented, causing longer and longer read times and poor performance.
Loss of Control - This may sound strange, but I mention it because I have a problem (Pack Rat Syndrome ?) of grabbing everything I can from the Internet. I should say, every FREE program I can. When you start installing so many programs, occasionally you may come up with a virus, spyware or adware. Know what you're installing, and only download from a reputable source. Also, when you download as I once did, you wind up with massive amounts of junk, you'll have programs you've never used, and some that you probably will never use. All it's doing is taking up space, slowing the computer down, and making it harder to find what you're really after. Dump what you don't use, or better still, don't get it in the first place. Make your computer lean and mean.
Why Make More Work - As obsessive as I am about most things, I'm the same way about keeping my programs current. It goes without saying, the more programs that you have, the more that you need to keep updated. Most programs have adapted a simple menu driven update procedure, but when you have dozens of programs to update, it can be a chore to keep up with. If you're like me, you use several different programs daily, but hopefully you're not like me in the fact that I, many times, have more than one program that performs the same task. Find the one that handles the job at hand, and dump the others.
This simple document was more of a wakeup call to get you to think about endlessly dumping anything and everything onto your hard drive. You should know how to use the Defrag utility in your System Tools folder, and also have a look at some of the excellent third party programs available to make your computing easier and more efficient.