Tactics reminiscent of a close presidential race seem to be popping up in Microsoft Corp.'s rivalry with Apple Inc.

Just a few weeks ago, the software maker, tired of being the butt of Apple attack ads, launched a positive series of commercials highlighting the diversity and coolness of Windows users. But then in the hours before this week's product announcement from Apple, Microsoft went negative.

A Monday evening e-mail from Microsoft's outside PR firm titled "Why You'll Find Better Value in Windows PCs than Macs" aimed to deflate anticipation that that Apple might unveil a cheap-by-Apple-standards $800 laptop. (The rumors were off by $200).

Microsoft laid out its talking points — among them that Windows PCs come with more power and features for lower prices, while Macs are even pricer than they look because they don't come with enough software.

In true political style, Microsoft trotted out a hidden "Apple tax," an extra $1,000 or more Microsoft says people switching from PCs to Macs must pay to "rebuy" software and hardware for their new system.

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