Maybe Microsoft should bring Lauren aboard full-time. Reporting its quarterly earnings today, the Redmond company said its research shows a 10 percent increase in preference for Windows PCs since the launch of its recent ad campaign.

The overall campaign dates to the company's Bill Gates and Jerry Seinfeld ads from last year. Those were head-scratchers, but the more recent "Laptop Hunters" ads -- starring bubbly Lauren and others searching for new PCs -- have been praised as particularly effective in positioning Macs as overpriced and Windows PCs as better values, offering similar or better specs for less money.

Microsoft cited the change in perception on its earnings conference call with analysts today, without going into more detail or context. We've asked the company for additional information about the research, including its methodology, time frame and the actual percentage of respondents who preferred Windows PCs before and after the ads. We'll update this post depending on the response.

To be sure, the ads were no match for the difficult economy. Quarterly revenue fell 16 percent, to $3.4 billion, in Microsoft's Client division, which makes Windows for PCs. The company cited a 7 percent to 9 percent decline in overall PC shipments.

Apple yesterday reported a 3 percent decline in Mac sales, although the company's overall results were up for the quarter.

Microsoft, which makes Office for Macs, said in a regulatory filing today that "Sales of application software for Apple’s Macintosh computers declined 63%, reflecting the launch of Mac Office 2008 in the prior year as well as a decline in sales of Apple computers."