How can I avoid infection? (Computer virus)

There is no way to guarantee that you will avoid infection. However,the potential damage can be minimized by taking the followingprecautions:
make sure you have a clean boot disk - test with whatever (up-to-date!)antivirus software you can get hold of and make sure it is (and stays)write-protected. Boot from it and make a couple of copies.
* use reputable, up-to-date and properly-installed anti-virussoftware regularly. (See below) If you use a shareware packagefor which payment and/or registration is required, do it. Not onlydoes it encourage the writer and make you feel virtuous, it meansyou can legitimately ask for technical support in a crisis.
* do some reading (see below). If you're a home user, you may wellget an infection sooner or later. If you're a business user, it'llbe sooner. Either way you'll benefit from a little background.If you're a business user you (or your enterprise) need a policy.
* don't rely *solely* on newsgroups like this to get you out oftrouble: it may be a while before you get a response (especiallyfrom a moderated group like comp.virus), and the first responseyou act upon may not offer the most appropriate advice for yourparticular problem
if you use a shareware/freeware package, make sure you have hardcopy of the documentation *before* your system falls apart!
* always run a memory-resident scanner to monitor disk access andexecutable files before they're run.
if you run Windows, a reputable anti-virus package which includesDOS *and* Windows components is likely to offer better protectionthan a DOS only package. If you run Windows 95, you need a properWin95 32-bit package for full protection.
* make sure your home system is protected, as well as your work PC.
* check all new systems and all floppy disks when they're broughtin (from *any* source) with a good virus-scanning program.