Amazon pulled the offering around 3:30 p.m. PDT after several hours of showing the full version of Windows XP Professional for $299.99 and the upgrade version for $199.99.
An Amazon spokesman said the premature offering was caused by a "glitch."
This is the second glitch that has caused Amazon to prematurely take preorders for Windows XP before Microsoft reveals pricing for the software, which it is expected to do any day.
"We have not yet announced pricing," Microsoft spokesman Frank Shaw said Thursday, before Amazon had removed the preorder pages. "You can expect that (the Amazon preorder pages) won't be up there for very long."
Amazon spokesman Bill Curry declined to comment about whether the prices that Amazon had advertised for XP would be the same as Microsoft's list price. But he said that if Microsoft's prices end up being higher than those Amazon posted, Amazon will make up the difference.
"It was our mistake," Curry said. "We'll protect our customers and make sure that they pay the lower price."
Amazon had not been contacted by Microsoft on Thursday. Asked whether Amazon owed the software maker an apology for jumping the gun on XP for the second time, Curry responded, "If it's an issue we'll do what's right."
Windows XP will be more expensive than Windows Me and 2000, costing anywhere from $10 to $20 more depending on the version. The full and upgrade versions of Windows 2000 have list prices of $320 and $220, respectively. A number of retailers, however, including Amazon, discount the upgrade version to $190 and the full version to $280.
Although Microsoft won't begin retail sales of Windows XP until Oct. 25, consumers will be able to get their hands on it before then. Microsoft will allow PC makers to start selling Windows XP desktops and notebooks Sept. 24.
The software giant plans to hand off the final Windows XP code to manufacturers Friday in a press event at the company's Redmond, Wash., headquarters. With the final code, PC makers can start to load the operating system onto computers.
CNET News.com's Michael Kanellos contributed to this report.