Lenovo's CEO said sales of its Windows 8 PCs have been "normal," neither surpassing nor falling behind expectations, but added that convertible devices using the OS are helping the company break into the high-end segment for the North American market. "In the past, we could only sell $299, $399 products. It's very hard to make money," said Yang Yuanqing on a Wednesday conference call. "That's the first time we not only had a presence in the high-end of the PC, but it also definitely helped us improve the margins."