Microsoft on Tuesday released a beta version of its new free anti-virus offering, Microsoft Security Essentials (a.k.a “Morro”). My review, in short: the program is a fast, easy to use and unobtrusive new addition to the stable of free anti-virus options available today. MSE is basically the next generation of Microsoft’s Windows Live Onecare anti-virus and anti-spyware service, but without all of the extras, such as a firewall, data backup solution or PC performance tuning (Microsoft announced in Nov. 2008 that it would stop selling Onecare through its retail channels at the end of June 2009). The toughest part was getting the program installed. MSE can run on Windows XP, Vista or Windows 7 (both 32-bit and 64-bit versions), but it failed to install on an XP Pro system I tried to use as my initial test machine — leaving me with nothing more than a failure message and cryptic