Google (NASDAQ: GOOG) Apps is a set of server-based word processing, spreadsheet, and presentation software created to go after a number of the features of Microsoft (NASDAQ: MSFT) Windows. While Windows uses the memory of the PC, Google's product runs over the internet on Google's servers.

Microsoft is getting sick of having sand kicked in its face. The big software company said that it would increase "the availability of its online services for e-mail and collaboration software," according to Reuters. The software had been available to smaller businesses but now it can be used by companies of any size.

Google claims that it has signed up 500,000 businesses to use Google Apps. That has to be a real headache for Microsoft.

Now, Redmond is forced to walk a fine line. If it offers too many services over the internet at too low a price, it could cut into its profitable Vista franchise. Most of Microsoft's margins are based on Windows, its server software, and Office. If the margins on those fall, the company's stock price is likely to take a large hit.

The news is another example of how Google is bedeviling the world's largest software company and hitting it where it hurts most, in its large profit centers.

Microsoft's problem may be that it cannot do anything about the problem other than match Google's products and probably drop what it charges. It is an unhappy option.

Douglas A. McIntyre is an editor at 247wallst.com.