Steve Jobs' claims that his overpriced keyboardless netbook is not a PC have been dismissed as dafted by the shy and retiring Microsoft CEO Steve Ballmer.

In an interview at the D: All Things Digital conference in California this week, Ballmer dumped on the iPad. Ballmer said the iPad was just a new PC form factor and not a revolutionary new category. He said it was impossible to do notes with it in a meeting.

"To a man with a hammer everything looks like a nail," Ballmer pointed out.

Earlier this week at the same conference, Jobs predicted an inexorable shift from desktop personal computers to mobile devices such as smartphones and tablets, which he dubbed a "post-PC era". Ballmer said that PCs would be around for a long time to come and Windows was now getting a new lease of life in a new breed of touchscreen tablet devices.

He said that he thought that people are going to be using PCs in greater and greater numbers for years to come. Ballmer took a shot at Google, ridiculing it for peddling two different operating systems - Android and Chrome. Then he sheepishly admitted that Microsoft also had multiple operating systems, but that would be different wouldn't it Steve?