How to remove virus/malware from your pc

How can I tell if my computer has a virus?

If you can answer "yes" to any of the following questions, your computer might have a virus.

1. Is your computer running very slowly?

A common symptom of a virus is much slower than normal computer performance. However, there can be other reasons for slow performance, including a hard disk that needs defragmenting, a computer that needs more memory (RAM), or the existence of spyware or adware. For more information about spyware, see How to tell if your computer is infected with spyware.

2. Are you getting unexpected messages, or are programs starting automatically?

Some viruses can cause damage to Windows or some of your programs. The results of this damage might include messages appearing unexpectedly, programs starting or closing automatically, or Windows shutting down suddenly.

3. Is your modem or hard disk working overtime?

An e‑mail virus works by sending many copies of itself by e‑mail. One indicator of this is that the activity light on your broadband or external modem is constantly lit; another is the sound of your computer's hard disk continually working. These are not always symptoms of a computer virus, but when combined with other problems, can indicate a virus infection.

To check for viruses, scan your computer with an antivirus program. New viruses appear every day, so keeping your antivirus program updated is important. For more information about computer security, go to the Security at Home page on the Microsoft website. To learn how to remove malicious software (malware) from your computer, go to the Microsoft Safety Scanner webpage.

How do I remove a computer virus?

If your computer is infected with a virus, you'll want to remove it as quickly as possible. A fast way to check for viruses is to use an online scanner, such as the Microsoft Safety Scanner. The scanner is a free online service that helps you identify and remove viruses, clean up your hard disk, and generally improve your computer's performance.

path1:If you can connect to the Internet

If you can reach a website using your web browser, run an online scan.

To run the Microsoft Safety Scanner

1. Go to the Microsoft Safety Scanner webpage to download the scanner.



2. Click Download Now, and then follow the instructions on the screen.

path2: If you can't connect to the Internet

If you can't get to the Microsoft Safety Scanner online, try restarting your computer in safe mode with networking enabled.

To restart in Safe Mode with networking enabled

1. Restart your computer.



2. When you see the computer manufacturer's logo, repeatedly press the F8 key until the Advanced Boot Options screen appears.



3. On the Advanced Boot Options screen, use the arrow keys to highlight Safe Mode with Networking, and then press Enter.



4. Log on to your computer with a user account that has administrator rights.



5. Follow the steps above to run the Microsoft Safety Scanner.

For more information about different startup modes, see Start your computer in safe mode.

If you still can't access the Internet after restarting in safe mode, try resetting your Internet Explorer proxy settings. The following steps reset the proxy settings in the Windows‌ registry so that you can access the Internet again.

To reset Internet Explorer proxy settings

1. In Windows 7, click the Start button . In the search box, type run, and then, in the list of results, click Run.
   
   -or-
   
   In Windows Vista, click the Start button , and then click Run.
   
   -or-
   
   In Windows XP, click Start, and then click Run.



2. Copy and paste or type the following text in the Open box in the Run dialog box:
   
   reg add
   
   "HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings" /v ProxyEnable /t REG_DWORD /d 0 /f



3. Click OK.



4. In Windows 7, click the Start button . In the search box, type run, and then, in the list of results, click Run.
   
   -or-
   
   In Windows Vista, click the Start button , and then click Run.
   
   -or-
   
   In Windows XP, click Start, and then click Run.



5. Copy and paste or type the following text in the Open box in the Run dialog box:
   
   reg delete
   
   "HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings" /v ProxyServer /f



6. Click OK.


Restart Internet Explorer and then follow the steps listed previously to run the scanner.

Remove a virus manually

Sometimes a virus must be removed manually. This can become a technical process that you should only undertake if you have experience with the Windows registry and know how to view and delete system and program files in Windows.

First, identify the virus by name by running your antivirus program. If you don't have an antivirus program or if your program doesn't detect the virus, you might still be able to identify it by looking for clues about how it behaves. Write down the words in any messages it displays or, if you received the virus in email, write down the subject line or name of the file attached to the message. Then search an antivirus vendor's website for references to what you wrote down to try to find the name of the virus and instructions for how to remove it.

Recovery and prevention

After the virus is removed, you might need to reinstall some software or restore lost information. Doing regular backups on your files can help you avoid data loss if your computer becomes infected again. If you haven't kept backups in the past, we recommend that you start now.

How can I help protect my computer from viruses?

Protecting your computer from viruses and other threats isn't difficult, but you have to be diligent.

1. Install an antivirus program.

Installing an antivirus program and keeping it up-to-date can help defend your computer against viruses. Antivirus programs scan for viruses trying to get into your email, operating system, or files. New viruses can appear daily, so check the antivirus manufacturer's website frequently for updates. Some antivirus programs are sold with annual subscriptions that can be renewed as needed, but many are also available for free. Microsoft offers Microsoft Security Essentials, a free antivirus program you can download from the Microsoft Security Essentials website. You can also visit the Windows Security software providers webpage to find a third-party antivirus program.

2. Don't open email messages from unfamiliar senders, or email attachments that you don't recognize.

Many viruses are attached to email messages and will spread as soon as you open the email attachment. It's best not to open any attachment unless it is something you are expecting. Microsoft‌ Outlook and Windows Mail help block potentially dangerous attachments.

3. Use a pop-up blocker with your browser.

Pop-up windows are small browser windows that appear on top of the website you're viewing. Although most are created by advertisers, they can also contain malicious or unsafe code. A pop-up blocker can prevent some or all of these windows from appearing.

The Pop-up Blocker feature in Internet Explorer is turned on by default. To learn more about changing its settings or turning it on and off, see Internet Explorer Pop-up Blocker: frequently asked questions.

4. Keep Windows updated.

Periodically, Microsoft releases special security updates that can help protect your computer. These updates can help prevent viruses and other computer attacks by closing possible security holes. Make sure that Windows receives these updates by turning on Windows automatic updating. To learn how, see Turn automatic updating on or off.

5. Use a firewall.‌

Windows Firewall or any other firewall program can help alert you to suspicious activity if a virus or worm attempts to connect to your computer. It can also block viruses, worms, and hackers from attempting to download potentially harmful programs to your computer. To learn more about Windows Firewall, see Understanding Windows Firewall settings.

6. Use your browser's privacy settings.

Being aware of how websites might use your private information is important to help prevent targeted advertising, fraud, and identity theft. If you're using Internet Explorer, you can adjust your Privacy settings or restore the default settings whenever you want. For details, see Change Internet Explorer Privacy settings.

7. Turn on User Account Control (UAC).

When changes are going to be made to your computer that require administrator-level permission, UAC notifies you and gives you the opportunity to approve the change. UAC can help keep viruses from making unwanted changes. To learn more about enabling UAC and adjusting the settings, see Turn User Account Control on or off.

8. Clear your Internet cache and your browsing history.

Most browsers store information about the websites you visit, and information that websites might ask you to provide (such as your name and address). While it can be helpful to have these details stored on your computer, there are times when you might want to delete some or all of them, for example when you're using a public computer and don't want to leave personal information behind. To learn how to clean up your history in Internet Explorer, see Delete webpage history and Delete your Internet cookies.