Those that were dragging their feet on downloading Microsoft Security Essentials will be disappointed to know that they are no longer able to obtain the download.

Less than 48 hours after making the beta program available, Microsoft has decided that they have enough participants and have closed it. Those trying to get in the beta now will receive this message: "Thank you for your interest in joining the Microsoft® Security Essentials Beta. We are not accepting additional participants at this time. Please check back at later a date for possible additional availability."

Those that were lucky enough to get in before Microsoft shut it down are providing some promising feedback for others. Not only is Security Essentials quite quick, but it is very easy on system resources. Reports are saying that it only uses about 4MB of RAM and processor utilization is also minimal.

Those in regions that Microsoft has not opened the beta for would do well to remember this. If you are looking to give Security Essentails a whirl, get your download ASAP before Microsoft decides it is full again.