Reinforcing its lead in the nascent touchscreen PC market, Hewlett-Packard Co. announced three new touch-enabled Windows 7 PCs on Tuesday, including two all-in-one desktops that let users control Web videos from Hulu and Netflix by tapping on the screen.

The TouchSmart 300, with 20-inch LCD screen, and TouchSmart 600, 23-inch screen, also come with small Windows 7 applications that let owners navigate Web services such as Twitter and two streaming music providers, HP Music Store by Rhapsody from RealNetworks Inc. and Pandora Internet radio.

All of the applications, except for Pandora's touch app, are exclusive to HP's TouchSmart 3.0 software suite.

The TouchSmart 300 will start at $US899, and the 600 will start at $US1,049. They will be available on Nov. 1 and Oct. 22, respectively. The official release of Windows 7 is slated for Oct. 22.

The TouchSmart 600 can be connected to an Xbox 360, PlayStation 3 or Wii game console via its HDMI or composite video inputs so that users can play games on its 23-inch screen.

HP also launched the TouchSmart 9100, a 23-inch touch-enabled all-in-one PC for business use. Aimed at hotels, stores, hospitals and schools, the 9100 starts at $US1,299 and is expected to be available in December.

Similar to the TouchSmart 600 on specs, the 9100 also includes Firewire ports for connecting digital video cameras, and the ability to lock down USB ports for more security.

The 9100 replaces the dx9000, which was launched at CES earlier this year.

HP also released an updated TouchSmart tx2 convertible laptop/tablet PC, which it first released a year ago. The new model comes with faster components and now starts at $US799.

Finally, the company released a 42-inch touchscreen LCD display for businesses that is designed for digital signage. The LD4200tm comes with 1080p (1,920 x 1080) resolution and will ship starting in December for $US2,799.