My computer has some viruses - Symantec Norton 360 for PC (037648318846)

• As soon as you suspect that your computer has a virus, remove your computer from any networks it might be on, as well as from the Internet, so that you don't inadvertently spread the bug to others.
• If you have virus-scanning (anti-virus) software installed, run it.
• If you don't have anti-virus software, you'll need to obtain some. If you can't get it from a network administrator or download it from an uninfected computer, you can mail-order it from a retailer.
• Start your computer (still not connected to a network) and follow the instructions that came with the anti-virus software.
• Keep running the virus-scanning software until your computer comes up clean.
• Reconnect your computer to the Internet and check with the anti-virus software's publisher to make sure you have the latest updates. If not, download them now.
• After updating the anti-virus software, run it again until your computer comes up clean.
Hopefully, it may help you to remove virus from your PC.

The best solution is to antivirus software despite that your computer is still vulnerable to any virus attach either but just surfing to internet or maybe you virus software is not up to date.

from your question, what are the kinds of computer viruses, here is the detailed explanation:

Computer viruses are generally defined as a program inputted into a computer that allows replication of the program installed. As it replicates, the program intentionally infects the computer, typically without even the user knowing about the damage being done. A virus, unlike worms or Trojan horses, needs an aid to transfer them to computers. Viruses usually take a large amount of computer memory, resulting into system crashes. Viruses are categorized to several parts based on its features.
Macro Viruses A macro virus, often scripted into common application programs such as Word or Excel, is spread by infecting documents. Macro viruses are known to be platform-independent since the virus itself are written in language of the application and not the operating system. When the application is running, this allows the macro virus to spread amongst the operating systems. There are thousands of macro viruses that exists, and each are considered major threats. Examples of these viruses are: Melissa.A and Bablas. pc.
Network Viruses Network viruses rapidly spreads through a Local Network Area ( LAN), and sometimes throughout the internet. Generally, network viruses multiply through shared resources, i.e., shared drives and folders. When the virus infects a computer, it searches through the network to attack its new potential prey. When the virus finishes infecting that computer, it moves on to the next and the cycle repeats itself. The most dangerous network viruses are Nimda and SQLSlammer.
Logic Bombs The logic bomb virus is a piece of code that are inputted into a software system. When a certain and specific condition is met, such as clicking on an internet browser or opening a particular file, the logic bomb virus is set off. Many programmers set the malicious virus off during days such as April Fools Day or Friday the 13th. When the virus is activated, then various activities will take place. For example, files are permanently deleted.
Companion Viruses Companion viruses takes advantage of MS- DOS. This virus creates a new file with typically the .COM extensions, but sometimes the .EXD extension as well. When a user manually types in a program they desire without adding .EXE or any other specific extention, DOS will make the assumption that the user want the file with the extension that comes first in alphabetical order, and thus running the virus. The companion virus is rare among Windows XP computers as this particular operating system does not use the MS-DOS.
Boot Sector Viruses Boot sector viruses generally hide in the boot sector, either in the bootable disk or the hard drive. Unlike most viruses, this virus does not harm the files in the hard disk, but harm the hard disk itself. Boot sector viruses are uncommon at this day and age because these viruses are spread rapidly by floppy disks and not on CD-ROMs.
Multipartite Viruses Multipartite viruses are spreaded through infected media and usually hides in the memory. Gradually, the virus moves to the boot sector of the hard drive and infects executable files on the hard drive and later across the computer system

• As soon as you suspect that your computer has a virus, remove your computer from any networks it might be on, as well as from the Internet, so that you don't inadvertently spread the bug to others.
• If you have virus-scanning (anti-virus) software installed, run it.
• If you don't have anti-virus software, you'll need to obtain some. If you can't get it from a network administrator or download it from an uninfected computer, you can mail-order it from a retailer.
• Start your computer (still not connected to a network) and follow the instructions that came with the anti-virus software.
• Keep running the virus-scanning software until your computer comes up clean.
• Reconnect your computer to the Internet and check with the anti-virus software's publisher to make sure you have the latest updates. If not, download them now.
• After updating the anti-virus software, run it again until your computer comes up clean.

Viruses are programs that get into your computer environment without your knowledge and then use your computer to connect to other computers and install a copy of themselves in those computers adn thereby spread. Virus programs are usually not content to just spread. After replicating, a virus program may do a silly prank, harm to your computer by corrupting files or even destroy its ability to serve you. Virus programs may also give a hacker a back door into you computer and thereby allow the hacker to use your computer to clog other sites or to steal your identity. If you think you have one disconnect from the web immmediately and remove it with anti virus pattern recognition tools. Avoid the free ones. Use a major product that large companies depend on. An anti virus program can be a virus itself.

Listen up, I have had a pretty bad virus on my computer before where this guy hacked in and created his own user account on my computer! Will, I noticed that my computer was detecting any viruses! Thats because he put a virus on my virus detector, so it couldnt detect viruses! I downloaded a different virus detector and got his viruses off of my computer right away! Try downloading a different virus protecter and try that!