For those of you who carry USB drives with utilities to help diagnose and clean other people’s machines, a utility you might want to take a look at is Dr. Web CureIt.
This is a FREE anti-virus and anti-spyware utility based on Dr.Web Anti-virus scanner, which will help you quickly scan and cure, if necessary, a computer operated by MS Windows 95OSR2/ 98/Me/NT 4.0/2000/XP/2003/2008/Vista/7 without installation of the Dr.Web Anti-virus.
Since the utility does not require installation, you could have it on your flash drive and run it as needed. This can be an ideal suppliment/alternate scanner to run in the event the machine already has anti-virus present.

Jason Faulkner is the man who brings you our daily tips. He is based in Atlanta, Georgia.
The problem is you need multiple anti-malware software to catch the bad stuff. No one anti-malware software package catches them all. The good part is that something is better than nothing.