NX: If you _absolutely_ can't have your documents stolen then you shouldn't even _ever_ have them on a computer that attaches to the internet.... period. Clearly this one is/does and viruses are the least of your problems.

You have three choices really:-

1. Buy another computer that you will use to connect to the internet and never connect the current one to it or the internet.
2. Write the files to removable media, (Floppy, CD-RW, whatever), use a program that shreds the existing ones, never have the media in the computer when you connect to the internet and learn how to manage the risk.
3. Find the strongest encryption program you can for your operating system and encrypt the files in place with a very long and complex password. It will take years to decrypt them.

It's about managing the risk.... If your "documents" are porn and you are a well known public servant then actually the risk isn't that great. I'll still vote for you if you cut my taxes..... If you are a "spook" and have government crippling information there then you should probably be talking to your boss about a course in computer security.... See how it goes.... It's the risk that needs to be mitigated. Once the risk is understood there will be a cost associated. Once the cost, (it doesn't necesarily have to be in dollars and cents), is determined then the cost, (in dollars and cents), can be more accurately determined. You aren't going to spend a million dollars to make sure that your girlfriend doesn't find out about your porn collection..... But you might spend a million if you are an inventor developing a product that will make you 100 million..... See the point? In any case, the above three options are the basics......