Protecting your workbook from viruses? I presume you mean Excel workbook -
initially I thought you were referring to a notebook/laptop computer. But...

Excel files you create on your computer are not going to become magically
virus infected. If they get infected it is because you already have a virus
of some type on your system. So, to me, the topic's answer boils down to
"how do I protect my computer from viruses?" and to that I would advise:

#1 - User Education. There is nothing so protective as knowing where the
dangers lay waiting. I know people who've run without anti-virus (I wouldn't
recommend it) and have seemingly remained untouched by any. Nothing like a
healthy dose of paranoia to keep a machine clean. All the standard warnings
about not opening attachments from unexpected emails, using caution with
regards to web sites visited, using extreme caution in downloading files from
the internet.

#2 - (probably should have been #1) Do not run normally using an account
with administrator priviledges. This alone would prevent over 90% of any
malware from getting installed on a system.

#3 - Make sure that you have some type of firewall up and running before
connecting to the internet; either a software firewall such as the one built
into Windows XP and Vista, or a good 3rd party firewall such as ZoneAlarm.
For more permanent installations, a firewalling or even just a plain NAT
router makes a good inbound firewall. I prefer a firewall that works both
ways, so that if something nasty does slip in somehow, then the firewall will
alert me when it tries to call home.

#4 - Install a strong anti-virus application on your computer and keep it
updated. Use care in choosing which one you use. Fairly recent studies show
that the 'top 3' installed anti-virus platforms may actually be the least
effective because virus and worm makers are targeting their wares to slip
past them. The top-3 AV apps have over 90% of the market share of installs.
There are absolutely EXCELLENT alternatives to them: I use Kaspersky
Anti-Virus on all of my pre-Vista machines and those at my workplace. I'm
using ESET's NOD32 for my Vista systems.

#5 - Don't trust anyone! The person you receive a file from may not be as
cautious as you in their computer habits. They may be passing you a virus as
part of a "really neat file I found on the internet" or "hey, our buddy Sam
gave me this. It's great, thought you might be able to use it also" ... or
like the one time I did get infected --- received a Word document from my
boss for review and comment. Neither one of us was running anti-virus
software (back in the good old days) and I found out from someone who DID run
AV software that I was passing a Word macro virus around. The original
source of the file was actually a U.S. Govt web site!

#6 - Keep in mind that most viruses are invited into a system in some form
or fashion. That email attachment from an unknown source that tries to
entice you to open it with titles like "latest in nudes of [insert current
hot movie star name here] attached" or "look at this, it's hilarious". That
email attachment from a trusted source who has clue zero about internet
security or safety. The great FREE or almost free copy of
Windows/Vista/Office/Adobe Creative Suite/other desirable and fairly
expensive software package you download from the web from some site with a
rather dubious name like 'www.viruiiRus.com'.

Keep the machine clean and you'll keep your Excel workbook clean.

"Student" wrote:

I would like to know what are the methods available for protecting my
workbook from viruses? It's for an assignment i'd really appreciate the
assistance. Thanks