If you are looking to upgrade the version of Windows running on your computer to Windows 7 or are looking to build your own Windows 7 computer then you better get your hands on a copy of Windows 7 before they become extinct. Microsoft has announced that they have discontinued distributing retail copies of Windows 7 to retailers in October of this year.
For now there are still many companies like Amazon that have inventory left so you are not completely out of luck. And if you want an OEM version then they will still be available. The good news is that PC manufacturers will still be able to sell new computers with Windows 7 installed since there has not been a cutoff date announced for that yet. And companies with volume licensing agreements will still be able to do new Windows 7 installations.
Some people believe that Microsoft is doing this to try and boot (or force) the sales of Windows 8 to people in need of an operating system upgrade. Windows 8 accounts for around 9% of market share while Windows 7 stands at around 46% and Windows XP is still at 31%. If you are worried about support then you still have some time because mainstream Windows 7 support will end in January 2015 while extended support will expire in January 2020.