If I reformat my computer to wipe everything out & start like new, will it also wipe out viruses

will it wipe out viruses on my computer as well?

If I reformat my computer to wipe everything out %26 start like new, will it also wipe out viruses on my com....malware

Not it will not. Formatting a computer simply deletes the filing structure making it appear to your operating system that you have a clean partition. That is why you can "undelete" data from a drive. Formatting leaves programs intact.

Wiping a drive is a destructive process that overwrites your data. When you "Wipe" a drive it writes random characters to the spaces on your disk. In tis process once Wiped it cannot be undeleted.

There are several types of Wipes.

Quick Wipe. Overwrites one time

DoD Wipe (Department of Defense). Overwrites 7 times

Gutman Wipe. This will make a paranoid 38 overwrites.It will also take 36+ hours for a 20 gb hard drive.

To preform a Quick wipe (which is enough for most) I like and use Kill Disk. If you need more than one pass, which is highly unlikely, try Digital Dolly 1.0

If I reformat my computer to wipe everything out %26 start like new, will it also wipe out viruses on my com....norton 360

yes, it will delete everything. but if still can use the infected computer you could download anti-virus and clean it up.
That's the best ways to do it. After you do that get some free tools to protect yourself. There's a good list here of free antivirus and antispyware programs