Microsoft to Sell Windows 8 Upgrade for $40

Microsoft

has announced that it will offer Windows XP, Windows Vista, and Windows 7 users the opportunity to upgrade for $39.99.

According to

, the upgrade includes Windows 8 Pro, the most advanced version of the upcoming operating system. Due for release before the end of the year, Windows 8 features two prominent changes, including Metro -- a tablet-friendly tile-based menu that shows all of a user's programs. Windows 8 will also be the first Windows operating system to

. Consumers who purchase a new Windows 7 PC today can upgrade to Windows 8 for $14.99. Earlier this year, Apple

announced that it would allow customers who purchased a

to upgrade to Mountain Lion for free when it is released in July. Other Mac users will be charged $19.99 for the upgrade. Bloggers and tech reporters have been critical of both operating systems. Business Insider does not think that Apple should

for Mountain Lion, which reportedly lacks the level of changes that typically accompany an OS X upgrade. The Verge published a

of Microsoft's highly anticipated operating system, answering the question, "What is wrong with Metro and Windows 8?" In March, a former Microsoft employee launched a

campaign to encourage Microsoft to improve the operating system before it is released. Microsoft has not announced the official shipping date of Windows 8, but there have been several reports that point to

, giving Best Buy

and Amazon

plenty of time to stock up on Windows 8 PCs for the holiday shopping season. Currently, retailers are struggling to maintain stock of the

, which has reportedly

.