Security and Performance Issues
The dangers of computer viruses are often discussed, but you may not be aware of
other hazards that can jeopardize your privacy, damage your files, and cause frustrating
Fortunately, implementing some simple strategies can not only secure your computer
and keep your data safe, but can make your computer work faster and more efficiently.
- Reviews the risks for a computer with excessive clutter, speed and performance
drains, insufficient security protection, and corrupted settings.
- Suggests repairs and preventative measures that can both protect your computer
and improve its speed, stability, and efficiency.
- Provides definitions of key computer and security terms.
Security and Performance Terms Defined
Risks posed by unneeded files
Every time you work on your computer or browse the Internet, temporary files, cache
files, and cookies are saved to your hard drive. Most of these are files that you
will never use and do not need to save. More unneeded buildup occurs from deleted
files accumulating in the Recycle Bin. All this debris clutters your computer and
overtaxes its resources.
- Reduction in processing. Unneeded files consume memory and take up drive
space. Instead of focusing on processing the services you really need, your computer
is using resources to process useless items.
- Recurrent crashes and lock-ups. A glut of unnecessary files increases drive
fragmentation, which burdens the hard drive. With an excessive amount of debris,
Windows can start to behave in unusual ways, including locking up or crashing.
- Endangered privacy. Anyone who has access to your computer can see the
Web sites you have visited and easily open files you have deleted.
- Erase temporary files. Simply deleting files from your Web browser cache
or temporary directories does not completely erase these tracks. Most security advisers
recommend using software that can thoroughly clean out cookies, temporary Internet
files, and cache files.
- Empty the Recycle Bin. Windows stores deleted items in the Recycle Bin
for easy recovery, and as you work on your computer, these deleted files quickly
accumulate. Periodically empty the Recycle Bin to reclaim valuable hard drive space.
Note: Items left in the Recycle Bin also pose a privacy risk because these files
can be easily retrieved. Where confidentiality is critical, not only empty the Recycle
Bin, but also use a data wiping program to thoroughly obliterate data.
- Remove unneeded files and programs. Occasionally review the data you have
saved and installed. Delete the documents and files you no longer want and uninstall
programs you are no longer using. Consider archiving rarely used files to a CD or
other removable media.
Risks posed by speed and performance drains
Various inefficiencies can bring your computer’s processing to a crawl, including
fragmented hard drives, splintered system memory, scattered registry entries, and
unneeded programs starting with Windows.
- Slow boot times. Various programs and services are set to load when Windows
loads. Some of these programs, such as antivirus protection, are desired, but many
are useless and needlessly slowing the time it takes to start your computer.
- Reduction in processing. When hard drives and system memory become fragmented,
computer performance is significantly slowed. Files take longer to open and programs
take longer to start.
- System and file damage. Highly fragmented files are more prone to becoming
corrupt. A highly fragmented hard drive places more strain on the heads, which in
severe cases can lead to a head crash and a loss of data.
- Exposure to infections. Trojans (malicious software) might also be loading
at startup. Trojans are usually designed to load when you restart your computer.
- Defragment your hard drive and system memory. Defragmenting your hard drives
reorganizes scattered data, which boosts file access speed and extends the life
of the drive. Defragmenting system memory reclaims valuable memory and improves
PC efficiency and speed.
- Compact the registry. Compacting the registry reorganizes entries, which
maximizes free space and improves the efficiency and speed of registry processing.
- Remove unneeded services from startup. Eliminate startup items that are
unnecessary. Removing these unneeded performance drains will boost your PC’s speed,
particularly the time it takes to boot, and will eliminate potentially dangerous
Risks posed by malicious software
Computer viruses, hackers, and other Internet dangers continue to pose a high risk.
A range of malicious programs (viruses, worms, Trojans, etc.) are designed to damage
computers or obtain confidential information from them. These infections can wreak
havoc by causing permanent computer damage, destroying data, and enabling identity
- Reduction in processing. Infections can cripple a system and bring processing
to a halt. Viruses can make dangerous changes to the vital registry, causing system
slowdowns and crashes.
- Lost files. Your files – treasured photos, valuable music, important financial
records – can all be destroyed if your computer becomes infected.
- System and file damage. Viruses are designed to alter the operation of
a computer. In addition to damaging files, viruses can harm your registry, your
operating system, and even your hardware.
- Data and identity theft. Trojans can enable the theft of any data saved
on your computer, including banking and credit card information, passwords, address
books, and other private information.
- Financial risk. The monetary cost of recovering from data loss or identity
theft can be devastating.
- Spreading of infections to others. You can unknowingly spread viral infections
to your friends, family, and business associates just by sending an email or leaving
your computer unattended. Hackers can secretly take control of your PC and use it
to attack and infect other computers.
- Use a firewall. A firewall is vital to secure Internet activity. A firewall
puts up a barrier against hackers and other intruders, but allows the Internet access
that you do want. Configure the firewall so that only the programs and Web sites
you trust are allowed to pass through.
- Use antivirus software. Antivirus software is a must-have for anyone who
uses the Internet. This software blocks computer infections and detects and removes
any existing infections. Make sure you keep the virus signatures up to date for
- Patch known security flaws. Many malicious programs exploit known security
vulnerabilities in operating systems and browsers. Install the latest security patches,
or use a specialized program that can automatically repair these flaws.
- Only download trusted programs. Only download programs from trusted Web
sites or refer to a trusted source for information. Do not install software if you
are not sure about it.
- Back up important files, including the registry. Establish and follow a
schedule for regular backups of your data. Ideally, use a backup program that backs
up all files, including programs and hidden operating system files. Regular backups
of the registry are also recommended to protect its critical settings.
- Permanently erase deleted confidential data. A file deleted through Windows
is not completely erased; even though you can't see the file, someone using easily
available tools can recover it and view its contents. For highly confidential data
you have deleted, use data wiping software that completely erases all data remnants.
Risks posed by corrupted settings
Over time and with regular usage, a computer can slowly degrade and become unstable,
with frequent crashes, perplexing error messages, and a host of other unexpected
nuisances. Some defects that can crop up over time are invalid registry references,
broken shortcuts, hidden spyware, obsolete uninstallation files, and physical errors
on the hard drive and other devices.
- Reduction in processing. Unneeded uninstallers and other invalid data in
the registry overburden Windows processing. Spyware wastes system memory and can
slow or stop Internet processing and lead to overall sluggish performance.
- Recurrent crashes and lock-ups. Damaged hard drives, spyware parasites,
obsolete shortcuts, and inaccurate registry references frequently cause computer
crashes and lock-ups. A volatile computer is extremely frustrating and can become
- Exposure to infections. In addition to burdening system memory, spyware
has been used to deliver Trojans and viruses. Any program designed to install on
a computer without the user’s knowledge carries a potential security risk.
- System and file damage. Damaged sectors on a drive can prevent files from
being accessed or saved and can cause system crashes. Spyware often incorporates
poorly or carelessly designed functions that can harm your computer’s operating
system and cause conflicts with your valid software.
- Use spyware removal software. Spyware is created with covert techniques
that make it difficult for people to spot. The safest approach is to use software
that scans for and deletes spyware. Note: Do your research when dealing with unknown
vendors. Some spyware removers advertised as “free” are actually spyware themselves,
or contain Trojans and viruses.
- Repair hard drive errors. A damaged hard drive can prevent you from saving
files and retrieving existing files. Using software to fix hard drive errors protects
your data and improves PC stability.
- Repair registry errors. The registry is vital to your computer's ability
to run correctly and when it becomes corrupted, overall degraded performance occurs.
Most technical advisors recommend that specialized software be used to make registry
changes, rather than making manual changes.
- Be cautious of so-called “free” programs. Free programs, such as file-sharing
software, screen savers, and games, are regularly bundled with spyware. Disclosure
of spyware is often hidden in the fine print of a license agreement. Be sure you
understand what is packaged with a program before you download it.
Adware is software that generates advertisements, usually as banner ads or pop-up
windows. Adware is usually bundled with other software and installed without your
knowledge. While usually not physically damaging or outright malicious, the intrusive
behavior of adware can be annoying and waste system resources.
Cache files are used to store information on a temporary basis for quick access.
A common example of a cache file is a browser cache. Every time you open a Web page,
your browser creates a cache file (a temporary copy) of the page's text and graphics.
When you open the page again, your browser checks the Web site server for changes.
If the page hasn't changed, your browser loads the page from cache on your hard
drive, which is much faster than originally loading it from the remote server.
A cookie is a small text file that some Web sites save to your local, hard drive
while you are browsing the site. Cookies contain identifying information, such as
log in and shopping cart information. Cookies are useful for loading Web site preferences
and login settings, but they can also contain information that can be passed to
others without your knowledge, usually for advertising purposes.
Over time, as you create, delete, and download files, your computer cannot store
data as one unit and instead will split it up and store pieces in various drive
locations. A fragmented hard drive has a large amount of such scattered data and
can significantly slow PC performance. Similar to hard drives and other storage
media, system memory can also become fragmented with time and usage.
Defragmenting reorganizes data so that components are stored closer to each
other. Regularly defragmenting hard drives and system memory improves drive speed,
reclaims valuable memory, and extends the life of your computer.
Malware (MALicious softWARE) is a generic term covering a range of software programs
that are designed to damage computers or to obtain unauthorized information from
computers. Some specific types of malware include viruses, worms, and Trojans.
The registry is a database that holds configuration settings used by your Windows
operating system. The registry is vital to your computer’s ability to run correctly.
It stores key data that Windows requires and continually references, such as user
profiles and settings for installed software and hardware.
Only manually edit the registry if you know what you are doing; making inaccurate
modifications can severely damage your computer. Always back up the registry prior
to making any changes.
Spyware is tracking software that is installed on your computer without your notice
or consent. It sends information about your computing activities back to its source,
usually for advertising purposes, but sometimes for much more dangerous purposes
such as identity theft or credit card fraud.
The effect of spyware varies depending on what its creator’s intentions are and
can include consumption of valuable system resources, random lockups, crashes, or
slowdowns; Web browser Home page or search page redirection; unwanted software installation;
and random or incessant pop-up ads.
A Trojan, or Trojan horse, is a software program that appears to be desirable or
useful, but intentionally does something you do not expect. The effects of Trojans
can range from simply displaying pop-up ads to destroying files or enabling the
theft of data.
Trojans are distributed in executable files, such as through email attachments,
CDs, and Internet downloads. People can be lured into installing a Trojan because
it appears that it will serve a legitimate purpose. Unlike viruses and worms, a
Trojan is not designed to make automatic copies of itself. However, Trojans can
carry viruses and other malicious software within them.
Two specific types of Trojans are keyloggers and RATs:
- A keylogger, or keystroke logger, captures all keystrokes and then records that
information to a log file. With a keylogger, a hacker can capture your logins, passwords,
credit card numbers, and any other confidential information that you type. Once
collected, this information can be silently transmitted to the Trojan’s creator
for malicious purposes, such as credit card or bank fraud.
- A remote access Trojan (RAT) gives someone remote access to and control of a computer.
With a RAT, imposters can send email messages that will appear to be from you; read,
modify, or destroy your documents; and use your PC to attack and infect other computers.
A computer virus is a software program designed to alter the operation of a computer.
Most viruses are malicious and intended to cause damage, but even a benign virus
can harm a system. Viruses can damage files, software programs, the registry, and
Viruses are distributed in executable files, such as through email attachments,
CDs, and Internet downloads. A virus infection occurs when the infected file is
run. A virus also automatically replicates, or makes copies of itself, by secretly
embedding its programming code into other programs.
The term “virus” is often used as a generic, collective reference that includes
other types of malicious programs, such as worms and Trojans.
A computer worm is a software program designed to reproduce and spread among computers.
Most worms are malicious and intended to overwhelm system memory or network bandwidth.
Worms can crash an entire network of computers or an individual computer.
Worms are generally distributed in email attachments or through unprotected Internet
activity. A worm spreads very rapidly because it is self-contained. It replicates
itself and, unlike viruses, a worm does not need to infect another program to spread.