It was an honest mistake, really.

Long recognized for its competition in the browser space, it appears that Microsoft’s anti-viral software has on occasion “accidentally” deleted Google Chrome from the hard drives of users’ Window-based computers, according to media reports. The software was apparently mistaking Chrome for a trojan horse.

“The trouble stems from a bug in the company’s antiviral security suite, an inconspicuous slice of software dubbed Microsoft Security Essentials. It’s a freebie utility that bundles real-time antivirus and malware scanning under one rooftop. In the splashy marketing slides on the product site, Microsoft calls it ‘anti-annoying,’” reported Time’s Techland.

But apparently, the product was in fact, annoying.

One user, “chasd. harris,” complained upon starting up their PC on Sept. 30, a Windows Security box popped up indicating a security problem that needed to be removed. 

“I clicked the Details button and saw that it was ‘PWS:Win32/Zbot.’  I clicked the Remove button and restarted my PC. Now I do not have Chrome,” Harris wrote on Chrome’s message board. “Was there really a problem, or is this just a way for Microsoft to stick it to Google?  If I reinstall Chrome, will it have my bookmarks and other settings?  Not sure what to do about this, but I much prefer Chrome to Explorer.”

Google employee Jacky H promptly replied Oct. 1 with this helpful tidbit:

1. Please be cautious when allowing exceptions in antivirus or protection software; there are legitimate trojans that are included in the MS Security update, Zbot included. 

2. Chrome was incorrectly identified as a Zbot by Microsoft as per their official messaging here: http://goo.gl/hqIVZ

3. Microsoft has released an update to MS Security that reverses this incorrect identification; this update is included in all MS security updates with the signature 1.113.672.0 and higher.

Within a few hours, Microsoft released an update that addresses the issue. Now that the issue has seemingly been rectified, Chrome fans can carry on as usual.