1. Introduction
It really bugs me when people refuse to install things on the premise that it will "slow down their computers". In reality, the programs that reside on your computer are just idle bits on your hard drive. So, is there some truth to this myth?

2. Program Installing
Often, programs that are aimed towards computer-literate users will come as a portable application without a complicated install process. (i.e. CPU-Z) These programs are good to go by themselves completely. Other programs require specific drivers and dependencies that must be installed on your computer before they can be run. (i.e., Adobe CS4)

However, most programs are targeted towards common users who have no knowledge of their inner workings. All programs share qualities that may or may not affect system performance. Here are some of them:

-Active Usage-
When a program is running, it will inevitably consume CPU clocks and system memory. Usually, this isn’t a problem. Nonetheless, high-end media editing programs may consume enough resources to lock up your computer.

-Background Processes-
Background processes are the daemons and updaters that run in the background automatically. These will generally start along with your Windows and may slow down system startup. If you don’t want these background processes running, you can easily remove them with MSConfig.

-File Fragmentation-
On a hard drive, files are stored in adjacent cells using magnetic charges. As you move files around and write over old ones, your files get messy and are harder to find. This natural process is collectively called file fragmentation. With large programs such as Microsoft Office or Adobe Creative Suite, fragmentation can become a serious bottleneck in system performance. However, many methods exist to combat this process. You can read more about reversing file fragmentation at my blog.

3. Conclusion
So, having a clean desktop without the clutter of programs is nice, but next time, don’t be so suspicious of programs that slow down your computer. If you take precautions, you can keep your computer clutter-free.