I recently upgraded my version of Windows 7 to "Ultimate" and installed the "XP Mode" virtual machine, in order to run some badly-needed XP software that won't run in Windows 7 and that I can't afford to upgrade. When I ran the XP Mode, I got a message to the effect that my computer was unprotected because no AV was installed. I checked on the Internet, and found that an AV was indeed needed for the virtual machine. Since I use KAV as my main antivirus program, I decided to install it on my virtual machine as well. I went to the Kaspersky website and downloaded the trial version. At first the installation went reasonably well, but it eventually failed, and from that point on, nothing on my virtual machine would work. I couldn't even go into the Control Panel to uninstall Kaspersky! I eventually uninstalled the XP Mode program, and started over, installing AVG on the virtual machine. Thus far, everything seems to be working OK, but I wonder if there's some way to put Kaspersky on the virtual machine, since I prefer the level of protection it provides.