Microsoft gives users Windows 7 free for 13 months

A new Internet worm that displays an image of President Obama is likely a prank by a student, several security experts speculated on Thursday.

Walling Data, a distributor of AVG security software, said the worm it discovered on computers at an Illinois grade school spreads via external devices like USB drives and network shares. Once a week, on Mondays, it displays a photo of President Obama's face in the lower right corner of screens on infected computers, but otherwise appears to be more of a nuisance than a threat.

Screen shot of Antivirus 2009

Antivirus 2009 is a new rogue anti-spyware program from the same family as Antivirus 2008 and Doctor Antivirus . Antivirus 2009 is installed and advertised through the use of misleading web sites that attempt to make you think your computer is infected with a variety of malware. Once installed, Antivirus 2009 will scan your computer and list a variety of fake infections that can't be removed unless you first purchase the software. These infections are fake, though, and only being shown to scare you into purchasing the software.

Official calls it 'old and inaccurate,' but researcher blames Apple's penchant for secrecy

The document, which had become the focus of considerable discussion among Mac users and security experts this week, is no longer available on Apple's support site. Instead, users who surf to its location are greeted with a generic message: "We're sorry. We can't find the article you're looking for."

"We have removed the KnowledgeBase article because it was old and inaccurate," Apple spokesman Bill Evans said in an e-mail Wednesday.

WASHINGTON (Reuters) - Spending a lot of time watching TV, playing video games and surfing the Web makes children more prone to a range of health problems including obesity and smoking, U.S. researchers said on Tuesday.

U.S. National Institutes of Health, Yale University and the California Pacific Medical Center experts analyzed 173 studies done since 1980 in one of the most comprehensive assessments to date on how exposure to media sources impacts the physical health of children and adolescents.