There are many programs on the market
that are designed to prevent and eliminate spyware (and adware), but
you don’t have to spend any money or download any third-party programs
to protect your system from these threats. You can use Windows
Defender, which comes with Windows 8 for free. Despite its focus on
spyware, Defender actually protects your computer from any potentially
unwanted programs. That includes many types of adware, Trojan horses,
and rootkits.
Windows Defender is designed to locate and
eradicate viruses and spyware. There are basically two ways to deal
with viruses and spyware. The best is to prevent them before they infect your system. The other is to detect and remove them after your computer has already been infected.
As you read earlier, viruses can cause a great
deal of harm to your computer. Therefore, it’s best to always run an
anti-virus program like Windows Defender.
Note
Windows Defender was a popular download
for Windows XP. It came free with Windows Vista, Windows 7, and now
Windows 8, so there’s nothing to download.
Spyware (and its close cousin adware) isn’t
specifically designed to cause your computer harm. But even without the
direct intent to do harm, spyware can have serious consequences. Too
much spyware can bog your system down, causing everything to run slower
than it should. Spyware can make unwanted changes to your Internet
settings, causing your web browser to act in unexpected ways. Spyware
can lead to many annoying pop-up ads. In the worst cases, it can send
personally identifiable information about you to identity thieves.
Most spyware comes from software that you can
download for free, such as screen savers, custom toolbars, and
file-sharing programs. However, it can also be installed automatically
from scripts and programs embedded in web pages.
Opening Windows Defender
You don’t need to open Windows Defender
to protect your computer. But you can do other things with Defender
that do require opening the program. As with most programs, you have
many ways to open Defender. Use whichever is most convenient for you at
the moment:
- From the desktop, press Windows+X, choose Control Panel, and choose
Small Icons from the View By drop-down list. Click Windows Defender to
launch it.
- From the Windows Start screen, display the Charms and click Search. Type def in the Search box and click Windows Defender.
When Windows Defender opens, it looks something like Figure 1.
Removing malicious software from your computer
Windows Defender offers many tools for
fighting malicious software. One scans your system for any malicious
program or file that you might have already acquired. On the Home tab
of Windows Defender, you see three Scan Options (shown in Figure 1):
- Quick scan: As its name implies,
the Quick scan takes less time because it focuses on areas where
malicious software is most likely hiding and because it checks only new
files and the kinds of files commonly used by viruses, spyware, or
other malicious software.
- Full scan: This takes a while
because it scans every file on your hard disk, but gives you the peace
of mind of knowing that your system is free of malicious software. A
full scan takes several minutes (or longer depending on the size of the
storage drives you are scanning), so you need to be patient.
Note
After you’ve done a single full scan, quick scans are sufficient.
- Custom scan: This lets you choose which drives you want to scan. More on this in the section “Performing a custom scan.”
To perform a scan, click the desired scan option and then click the Scan Now button (shown in Figure 1), and Defender starts scanning your system as shown in Figure 2.
When the scan is complete, you should see a clean bill of health. If not, suspicious items will be quarantined (disabled). You should be taken to the quarantined list automatically, although you can get there any time by choosing History 
Quarantined Items
View Details. You can see details on quarantined items, allowed items
(which are items you let run on your computer), or all detected items.
Each item in the quarantined list has an alert level associated with it. Here’s what each alert level means:
- Severe or High: This item is known
to compromise the security of your computer. Or this item may be too
new to be well known. But all indications point to malicious intent, so
the item should be removed immediately.
- Medium: This item appears to
collect personal information or change Internet settings. Review the
item details. If you do not recognize or trust the publisher, block or
remove the item.
- Low: This is a potentially unwanted item that should be removed if you did not intentionally install it yourself.
To remove an item, click its name and
click Remove. You can usually click Remove All, because valid, useful
programs are rarely detected as viruses, spyware, or other potentially
unwanted items. If in doubt, you can leave the item quarantined for a
while. Use your computer normally to see whether some useful program no
longer works. After you’ve determined that everything is okay, you can
go back into Quarantined Items and remove anything you left behind.
Should you ever encounter a false positive (where
an innocent program is quarantined), don’t remove it. Instead, click
its name and then click Restore.
