Microsoft’s next computer operating system, Windows 8, is officially up for pre-order, and the company is giving users several options for upgrading.

On Friday, the company’s blog listed four ways to upgrade to Windows 8.

■ For the physical media types: Users can reserve a packaged DVD of Window 8 Pro for $69.99 at Amazon, Best Buy, Staples, Office Depot, Microsoft stores and other retailers.

■ For the downloaders: Users can upgrade their devices on Oct. 26 — the day the system officially launches — for $40.

Both of those offers run through Jan. 31.

■ For the computer buyers: Users can also get Windows 8 with the purchase of a new PC or other devices. Sony, Asus, Acer, Dell and HP have all announced new computers that will run the upgrade.

■ For those who worry they missed the boat: If you just bought a Windows 7 PC, don’t despair. Users who purchased or will purchase an eligible PCs between June 2 and Jan. 31 can upgrade to Windows 8 for $14.99. To take advantage of that deal, users should register their qualifying PC at Microsoft’s Upgrade Offer Web site. Microsoft will then send a promotional code that gives access to the special price.

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