The Microsoft Security Essentials software for Windows was at fault for removing the browser, with both companies’ security teams were racing to fix.
It seems that the software falsely identified Chrome as a malware threat, and even after the web browser was restored Windows deleted it again.
Google was first out with instructions of how to deal with the problem on its blog, ahead of an automatic update over the weekend.
Microsoft meanwhile owned up to the mistake as “incorrect detection for PWS:Win32/Zbot” according to a statement, reports the Sydney Morning Herald, while apologising for any inconvenience.
Microsoft Security Essentialls was updated along with fix instructions.
No sign of an apology to Google, though, after Chrome was mistaken for a password stealing trojan.
According to security expert Graham Cluley at Sophos it is an embarrassing mistake from the Microsoft team, which managed to overlook Chrome in its tests.
“A human error has occurred, and the guys at Microsoft will be just as upset about this as those at Google,” he told TechEye.
“It isn’t particularly common for this to happen as the browser would usually be in a database for false positive testing, but it seems it was written too loosely and clearly it wasn’t in the system when scanning.
“It can happen to anyone, but it is particularly embarrassing despite prompt attempts to fix it as it will have caused many people problems.”