Those Apple "Get a Mac" ads have long been an annoyance to Microsoft and to Bill Gates in particular . No surprise as Apple, emboldened by rising market share, continues to ratchet up the venom with quips like, "fear of switching is the foundation of customer loyalty for PCs," found in its latest TV ad. Now Microsoft is fighting back.Microsoft's new $300 million campaign (one of Redmond's largest ever) is set to launch with a $10 million assist from "key celebrity pitchman" Jerry Seinfeld. Yes, Bill Gates will appear as well -- the once maligned, rich corporate nerd turned adorable, rich humanitarian nerd. The campaign is said to be based on the idea of "Windows, Not Walls," stressing the need to "break down barriers that prevent people and ideas from connecting." Something we think open-sourcers might have a laugh at. Anywho, the immediate goal of the campaign is to reverse the negative public perception of Vista and thus incorporates elements of the Mojave Experiment . While we have doubts about the latter , the combination of Seinfeld's pithy observations with a bit of that Bill Gates, self deprecating humor seen in " Bill's Last Day " could be a winning combination. Whether that turns the slow moving boat of public opinion remains to be seen.P.S. The campaign is said to debut on September 4th. Mulva.