Amazon.com has put online preorder pages for the USB flash drives containing Microsoft Windows 10 Home and Microsoft Windows 10 Pro, which will start shipping On August 30th. Windows 10 Home retails for $119.99 and both versions of Windows 10 Pro are $199.99.

Windows 10 will be available on USB drives for purchase in retail channels shortly after launch, according to Microsoft.

But Microsoft will also offer the new OS in DVDs, despite the obvious disadvantages if the optical medium - slower installations and lack of optical disc readers in many modern devices.

Windows 10 customers will have one year from July 29th to take advantage of a free upgrade. Once your Windows device is upgraded to Windows 10, Microsoft will continue keeping it current for the support lifetime of the device for free.

Microsoft's customers running on Windows 7 or Windows 8.1 are eligible for the free upgrade to Windows 10 within that first year of release, but the "Enterprise" editions of Windows 7 and Windows 8.1 are excluded from the upgrade offer. "Pro" editions are eligible for the free upgrade. But Windows RT, Windows Vista, Windows XP and pirated copies of any version of Windows are not eligible for the free upgrade.

Windows 10 is going to be the last numbered version of Microsoft’s operating systems. After Windows 10, Microsoft’s next operating system is going to be a paid subscription service simply called Windows.