A lot of people seems to know how much space does windows 10 really occupies and how
much free space do i need to upgrade to windows 10.The answer for this question is
simple.You need at least 8 GB of free space to perform successful upgrade.The next
question that may arise in your mind is what to do when you don't have Such amount of
space in your hard disk.
Then here are the few things you can try.
1.Uninstall/remove apps and programs that you no longer use.
Removing them will really free some space as the files that are associated with the program
will automatically deleted when we uninstall them,which results us to get some free space.
2.The next thing,we can do is using disk clean-up.
Disk cleanup is an inbuilt utility that are available in windows,to perform cleaning
operation.When we run this utility it will delete the unnecessary files,older restore points
and its related items to free some space.
For more details,regarding disk clean-up check this article.
3.Reduce the size of WinSxS folder...
WinSxS is an important folder available in windows directory,where our windows store its
important files like windows components,updates and other items.Deleting them will make
our system unstable,as Some critical issues like we can't restart and updates issues will
arise..
But we can reduce the size of that folder using task scheduler.
If you are using Windows 8.1,then
i).Open control panel.
ii) On the Search box(found on the top right corner) type Schedule tasks->select top most
result under administrative tools.
iii)Click on the arrow next to Task Schedule library,Navigate to
Microsoft->Windows->Servicing.On that Select/click StartComponentCleanup
(iv) Again click/tap run under the item that is selected.
That Will perform the above task.
4).You can also attach an external drive which contain some free space..but don't forget to
keep them in safe place if you need them for future.
That's it...
"Hope it is helpful"