Google's Executive Chairman and former CEO Eric Schmidt said that Microsoft's Surface tablet will mean a lot for the company, with one big catch – the product has to work.

Schmidt commented on Microsoft, among other topics and companies, in an interview with AllThingsD's Kara Swisher and Walt Mossberg on Wednesday evening. Although the Google executive spoke positively about Microsoft's upcoming Surface, he did maintain that Microsoft is not part of the "Gang of Four" most influential tech companies, which he says includes Apple, Google, Amazon and Facebook.

Microsoft has not yet released any "state-of-the-art products" into the major technology fields, according to Schmidt. But Surface could change this. The device is Microsoft's first foray into an integrated hardware and software product, something that Schmidt says the industry will start to see much more of. When asked if companies can make truly integrated devices like Apple, Schmidt pointed to Google's Chromebooks and Motorola Android devices as examples.

Though Google and Apple have the dominant lead in the smartphone and tablet space, Microsoft is preparing to offer competitive products, like Surface and Windows Phone 8. Schmidt recognized that Microsoft had a monopoly with the Windows operating system, but that business model won't solve the problems in the mobile market. He said that Google has already "evolved to a new model, like with Android."

Microsoft will release Surface on Oct. 26, with a launch event set for Oct. 25. The company has not allowed very much hands-on time with the device, so the answer to whether it works remains hazy.