Adobe recently announced that it wouldn't release Vista-compatible updates to current versions of many of its products. It may hope to increase revenue by forcing Vista users with older versions of Photoshop to upgrade, but I'm not convinced.

And given that users of existing, XP-certified Adobe products will have to waive their right to Adobe tech support if they upgrade to Vista, such a move could encourage some to opt for Microsoft products. These are at least guaranteed to run without hassles on the new OS.

Although running uncertified products on a new operating system tends to cause only minor problems, and Adobe is to issue some patches later in the year, it can prevent users from getting the most from an application they've shelled out a fortune to buy.

Adobe says its existing products were released before Windows Vista became publicly available, so they weren't fully designed for, or tested on, the new operating system. The company points out that its recently launched CS3 (Creative Suite 3.0) is Vista Compatible. Which is fair enough. But I'd be willing to bet that it also feels threatened by Microsoft's increasing interest in areas Adobe has been seen to dominate, such as image editing and web design.

With the release of its flagship product, CS3, Adobe is pitching for its biggest launch yet. Much rides on it – as CS and CS2 customers wait to upgrade, 2007 Q1 sales have slumped compared to the same period last year.

But if Adobe has got its sums wrong, disgruntled Vista users with existing Photoshop licences may decide to give CS3 a swerve and migrate to Microsoft's products. And while most designers and photographers use Macs, now that Intel chips and dual-boot systems are becoming popular, they're ripe for the plucking too. Could this be one occasion where two big players' software incompatibility hurts a vendor as much as it irritates the humble user? Time will tell.

Read our review of Adobe Photoshop CS3

Read our review of Adobe InDesign CS3

Read our review of Adobe Dreamweaver CS3

This article appears in the June 07 issue of PC Advisor, available now.