As Windows 10 is approaching towards release so is Microsoft ending support for its older products like Windows Xp whose support ended a 2 years ago. Today Windows 7, which is being widely used version of windows, is now shutting down its mainstream support.
According to Microsoft product support lifecycle database all version of windows 7, which includes Windows 7 Starter, Home, Home Premium, Ultimate, Enterprise, are not going to get free further help and support from Microsoft.
Microsoft seems to be targeting Windows 7 users to shift to Windows 8.1. Windows 7 mainstream support ends mean that you have to pay for any software issues in future but this does not mean that extended support will also be ended, it will end by 2020. However you should not worry as security patches will still be given by Windows 7.
Windows 7 was released in late 2009 and is widely used across world about 100 million users as it was stable release after Windows Vista. As for Window 10 is concerned it is rumored to be released on 21 January 2015.