Is there any difference between Paid Windows and Windows we download from internet or install from a DVD.
The image distributed on the media, when you purchase Windows from an authorized reseller, is identical to that of the ISO that can be downloaded from Microsoft. However, the image that is installed on OEM devices, is based on that default image but often is customized by the OEM.
Why the price of Windows is so high if, we can download it from the internet? Is there any difference between working and quality in both?
When you purchase Windows, you actually only pay for the license itself, not the media to install it. This has always been the case, but only recently, has Microsoft made it extremely easy to download Windows. In the past, it was possible to download a Windows ISO directly, if you knew about where to find it.
Is there any difference between working and quality in both?
The installation images are identical.
I am currently using Windows 8 and my other laptop have a free window installed. And i found no difference between them?
Windows is not free. OEM devices might come with Windows already installed but the cost of that license is built into the cost of the device. While you could upgrade to Windows 10 for free, between July 2015 and July 2016, the cost of that license was simply integrated into the cost of your existing license. The cost for a license is literally whatever Microsoft wants to charge for it. Even during the free upgrade period, if you did not already have an eligible Windows license, a Windows 10 license was not actually free.