tlcmd wrote:...run Windows XP within it using a virtual box or similar program. My question: Will Linux then protect that windows application for the evil beasties, viruses, malware, etc or will I still need an antivirus program to protect Windows...
Linux per se
is not going to do that for you, BUT, VirtualBox (for example), have provisions that allow you -- in different ways -- to protect a virtual machine from changes every time you boot into it. (1) Simplest is to make a backup copy of the virtual hard disk file. (2) Another way is the use of snapshots so you can roll back if things go wrong with a VM. (3) Yet another way is setting the virtual machine's virtual hard drive as immutable. IMSMR, at least option (2) can be set through VirtualBox's GUI. Option (3) can be set via command line. Option (1), obviously, just use copy-and-paste.
Using any of these schemes should be enough to protect a Windows VM from being changed, at least until next reboot. So, there's really no need to install anti-virus/-malware apps in a Windows VM unless of course it's an absolute necessity and/or you require pro-active protection.