Having sold some 1.5 million Windows-based computers, Toshiba saw it’s U.S. PC sales grow an impressive 50% in Q1. The sales, which were greatly aided by a recovering economy, were also accelerated thanks to interest in Windows 7. Toshiba is now the 4th largest mover of PCs in the U.S. As for the future, Toshiba’s GM of digital products has said the company is planning on introducing a series of tablets this year, with some running Microsoft’s Windows 7 and others Google’s Android. Some analysts have predicted that such a move would do nothing but throw a wrench into Toshiba’s netbook sales, but the company is confident that the two categories of devices can be sold side by side with minimal cannibalization. The U.S. market for tablets is expected to swell to 50 million units by 2014.