Security patches are necessary to fix unforeseen compatibility and functionality issues as well as security loopholes. These arise from flaws in the software that are exploited by cyber criminals in order to hijack or damage systems. Loopholes can be particularly dangerous if they allow an attacker to gain control of a system and execute commands, access data and pose as the operator of the system.

The main causes of a slow computer are:

- Spyware
- Corrupt and Erroneous Registry Entries
- A Combination of too many Memory-Intensive Programs and Insufficient Memory (RAM)
- Fragmented and/or Cluttered Hard Drive

The main cause of a slow startup is having too many programs configured to run automatically when Windows boots. A system can only juggle a limited amount of tasks at once, depending on the amount of memory installed. An installed program takes up space on your hard drive, but it also uses memory when it is being run.

The best way to protect your wireless home network is with encryption such as Wi-Fi Protected Access (WPA) or Wired Equivalent Privacy (WEP), or by restricting access to the unique Media Access Control (MAC) addresses of specific machines. WPA and WEP encryption uses a 128-bit password to keep out intruders, while a MAC filter compares the unique identity of an attempted connection with a list of accepted identities.

The most dangerous aspect of these public networks is that they are, by definition, open to access by everyone—even those with malicious intent. In the same way that leaving your home network open to unwanted users is dangerous; similarly, connecting to a public network with unverified users poses a security threat.

A firewall is a network security device that inspects network traffic and blocks or permits access based on a set of rules. Firewalls can be implemented as either software packages or hardware appliances. Much like a firewall that is constructed around a building or an engine to prevent the spread of heat and fire, a computer firewall establishes a perimeter around computer systems in order to protect them from dangerous or unauthorized elements.

The Windows Update website was introduced as a means of easily downloading and installing updates for the Windows 98 operating system. Since then, Microsoft has implemented this concept of accessible updates into its subsequent Windows releases. Today, the Automatic Updates feature provides users with the easiest way to keep their system protected against the latest security vulnerabilities.

Any application that does not uninstall properly, or does not have an uninstaller, can leave entries in the Windows Registry. These can build up over time, and lead to decreased system performance and stability. Furthermore, in most cases, uninstalling a program on one user account will not remove the Registry entries in every other user’s account configurations.

The Windows Registry is organized much like the Windows file system that is viewable in Explorer. At the top of the hierarchy are the main branches of the Registry, and each of these categories is called a Hive. Hives are composed Keys which can contain other Keys, as well as Values.

The Windows Registry is a central hierarchical database used to store information and settings for users, applications and hardware devices. It contains information that applications and system processes constantly retrieve and store during operation, such as a profile of user’s custom configurations, the types of documents that applications can open and create, as well as the hardware and network ports that exist and are being used.