Google's (NASDAQ:GOOG) Chrome security team has found that the free Microsoft (NASDAQ:MSFT) Security Essentials antivirus software falsely identifies the Chrome browser as a piece of malware (PWS:Win32/Zbot) and boots it from users' Windows PCs.
Affected users won't be able to launch Chrome or load new Web pages with the browser. Microsoft said on its malware protection Facebook page that it has already fixed the issue, but approximately 3,000 customers were impacted.
"Affected customers should manually update Microsoft Security Essentials (MSE) with the latest signatures. To do this, simply launch MSE, go to the update tab and click the Update button, and then reinstall Google Chrome," the Facebook page states.
Mark Larson, an engineering manager for Chrome, noted that if Chrome works fine for users, they are unaffected and needn't act.
Google, meanwhile, is releasing an update to automatically repair Chrome, but the company also released instructions to restore Chrome manually. See screenshots of the process here.
Just as Microsoft noted, before reinstalling Chrome, users must first update the signature files used by Microsoft Security Essentials on their computers. Users will then run Security Essentials by opening their Start menu, finding the Security Essentials program and launching it.
When the application loads, users must click the Update tab and press the large Update button. Users will verify the update when it's done by clicking the triangle next to Help, selecting About Security Essentials and verifying that the Antispyware definition is 1.113.672.0 or higher.
Users must then uninstall and reinstall Chrome. Users of Windows XP machines will start by going back to the control panel and double-clicking on Add or Remove Programs, selecting Chrome and clicking Remove.
Users may then confirm the removal, but Larson warns users should take care not to accidentally check the box prompting users to also delete their browsing data.
Users may then go to www.google.com/chrome in another browser to download and install Chrome anew.
Windows 7 and Windows Vista users have it a little easier. They will click Start, pick Control Panel, click Programs, then Chrome, and click the Uninstall button at the top of the list. Finally, they will go to the Chrome download Webpage to reinstall the browser.
Of course, Google has already begun repairing Chrome for affected users so no action may need to be taken-unless Chrome won't work for users.
Chrome, meanwhile, continues to gain traction, growing from 15.5 percent through August to 16.2 percent through September, according to browser tracker Net Applications.