Microsoft released its new free antivirus utility, Microsoft Security Essentials, today, September 29th, and it does the job adequately, but it snoops into your business and it's s_l_o_w.
Microsoft Security Essentials is the replacement for Microsoft's OneCare suite. It's meant to be an improvement on that older free program, but I don't any significant difference between the two. Since OneCare is history now, though, that doesn't matter.
Security Essentials runs on Windows XP, Vista, or Windows 7 (beta or release candidate) on both the 32 and 64-bit versions. The install program doesn't automatically pick out the right version of Windows; you'll have to do that. It's a small point, but I found it a little annoying, especially since Microsoft makes a big deal of telling you, in the license, that they'll be checking up on your PC and its programs from time to time without telling you.
To be exact, in the license Microsoft states that, it will automatically "send information about the software and your operating system to Microsoft. This information includes the versions of the software and operating system software." Later, Microsoft adds that it will also send the company "your Internet protocol address, the type of operating system, browser and name and version of the software you are using, and the language code of the device where you installed the software."
Of course, Microsoft also says that they won't use this information to identify you or to contact you. I don't buy that myself. I dislike any company that makes snooping on me part of the price of using their programs.
Once you're past that, the program installs and wants, as usual, to make sure its virus files are up-to-date before running its first check-up. In my case though it just told me that it already had the most up-to-date files and didn't start an automatic check or give me the option of running one. Again, it's not a big deal, but it is sloppy.
To see what it could do, I installed it on a Dell Inspiron 530S. This is powered by a 2.2-GHz Intel Pentium E2200 dual-core processor with an 800-MHz front-side bus, along with 4GB of RAM, a 500GB SATA (Serial ATA) drive and an integrated Intel 3100 graphics. This is not a fast PC, but it's perfectly adequate for running XP SP3.
The program does all the basics. Essentials automatically downloads virus and spyware definitions; provides real-time protection that scans downloads and attachments, and looks for suspicious file and program activity. It will also run an unattended whenever works best for you. The default is once a week on Sunday morning at 2 AM.
That's all well and good, but I found it to be surprisingly slow. A full system scan took two hours and ten minutes. In stark contrast, Avira, my current favorite free Windows anti-virus program, did the same job on the same machine the night before in just over an hour.
That was enough for me. There are faster, better made, and not half so noisy free malware protection programs out there. It's not that you'd be making a mistake going with Security Essentials it's just that you can easily do better with another freeware program.