Apple won't say how many people have downloaded the free software, but an executive said that it has been extremely popular since Apple chief executive Steve Jobs launched it on Thursday.
"The downloads have been going full tilt constantly," said Peter Lowe, Apple's director of marketing for applications and services. "We've been delivering a lot of Windows software over the last 24 hours."
The company's support discussion boards were filled with praise, concern over glitches and the usual gripes over what wasn't included -- in this case, support for additional music formats and digital music players beyond Apple's own iPod.
Many of those who have downloaded the software were Mac users of iTunes and said they were glad to be able to run the same software on Windows machines they used either at work or at home.
"I've been using iTunes at work for a couple years now and love it. However, I have never found anything nearly as good for Windows until now," said Keith Hanlon, a freelance musician who also works in marketing and Web design for a drum store in Columbus, Ohio. "I am thrilled that iTunes for Windows is exactly the same as the Mac version."
However, not everyone has been so happy with their iTunes experience on the PC. One of the most serious complaints came from a number of Windows 2000 Professional users, who said installing iTunes appeared to crash their machines.
Patrick Nielsen Hayden, a science fiction book editor in New York, said he installed the Windows version on his PC but then was unable to use his machine. "On restart, Windows 2000 Pro got up to its "splash screen" -- the screen displaying the product's logo. (It)got about halfway across the progress meter...and froze solid," he wrote in an email.
Hayden said the experience was "very discouraging" but that he would try again after reinstalling Windows. "I'm actually much more of a Mac person at home; it's just that we have this PC with a big hard drive, and I was hoping to park the household MP3 collection on it instead of (on) one of the Macs," he said. "Maybe it'll work on a second attempt."
Apple's discussion boards featured more than a dozen other people reporting similar problems.
Apple's Lowe said the company is looking into the issue.
"We have seen some isolated reports of people locking up after restart," he said. "We are investigating that."
Apple recommended that those who have the problem boot their machine in Windows' "safe mode" by holding down the Shift key while restarting and temporarily uninstall iTunes. Some customers also reported having problems while restarting in safe mode, though.
Among other gripes were complaints that iTunes re-categorised Windows users' music into new folders, although Apple said if the default settings are used, iTunes is not supposed to rename or move any music files.
In general, Lowe said, the reaction from both customers and reviewers has been overwhelmingly positive.
"We're really, really pleased with the reaction," he said.
