BEIJING, Oct. 23 (Xinhua) -- Microsoft on Thursday issued a public letter defending its "black out" tool to stamp out piracy in China and attempting to clear up "misunderstandings" over the measure.

    The software giant's program turns computer "desktops" black if the installed software fails a validation test, but it has been met with fury by Chinese computer users and renewed complaints over the price of genuine software.

    In the letter, the company stressed that it would not collect personal information via its Windows Genuine Advantage program, aiming to assuage fears of possible privacy infringements.

    "People are attaching more importance to intellectual property protection, but we notice there is still a long way to go," the letter said.

    The program launched just after midnight on Tuesday, turns the desktop black every hour and users must manually restart the desktop.

    With reports of "black screen incidents" hitting headlines in the Chinese media, major portal websites have launched on-line surveys of public attitudes to the move.

    A survey by qq.com showed that as of 4:30 p.m. on Thursday, 66.53 percent, or 29,555 people, strongly disapproved of the program, while another survey by www.sina.com.cn showed 87.44 percent, or 130,756 people, said the program would put them off buying genuine Microsoft products.

    "The black screen teaches us a better lesson than all preaching," said Ni Guangnan, a leading researcher at the Institute of Computing Technology of the Chinese Academy of Sciences and academician of Chinese Academy of Engineering.

    "Now people understand why China needs its own software, especially basic programs.... Aren't worse things likely to happen in the future?" Ni asked.