TiVo continued its push away from the set-top boxes Monday by unveiling a package that turns an ordinary personal computer into a digital-video recorder.

Alviso, California-based TiVo teamed with media software maker Nero to create Nero LiquidTV/TiVo PC. The kit, including a remote and TV tuner that plugs into a PC, is scheduled to go on sale October 15 for $199.

Amid a sharp downturn on U.S. exchanges Monday afternoon, TiVo’s shares fell $0.12, or 1.6 percent, to $7.24.

Kaufman Brothers analyst Todd Mitchell said the TiVo PC is yet another step in TiVo’s metamorphosis from a maker of set-top boxes to a software company.

“I think this is part of the overall shift in their strategy of going from a hardware-focused company to a software-focused company,” he said. “They’re following convergence.”

Earlier this year, TiVo began testing a software download that gives DVR customers of Comcast and Cox cable services a TiVo interface.

“It’s a better business model for TiVo,” said Mr. Mitchell, who noted that the company can tap a pending patent settlement from Echostar worth about $113 million as it transitions away from its original hardware business.

Closely held Nero, based in Karlsbad, Germany, makes software for burning CDs and DVDs. For PCs that already have a TV tuner, a $99 software package will be available.

TiVo has seen its set-top box subscription business shrink as cable companies like Cablevision, and telecom companies like AT&T and Verizon, offer their own DVR systems.

In addition to moving toward a software model, TiVo has been rolling out new services, such as a deal that lets TiVo customers order books, CDs and other products promoted on “The Oprah Winfrey Show” and “The Daily Show” via Amazon.com.