Upgrade Win10 RTM official version C disk is too small how to do?

We combined the information released by Microsoft and gave an ideal solution:
During the installation and upgrade process of Windows 10, Microsoft specially added a clever link. When the upgrade program detects that the system disk does not have enough free space. In addition to reminding users to manually clean up the space, there are two additional options available for the user to choose:
Select A• Insert a USB stick to get extra space, but it must be 16GB or more;
Select B• Choose another partition or link an external hard drive to get extra space (9GB or more);
Of course, it is most convenient to choose to use a USB flash drive. What? No U disk? Buy one, or use a card reader to plug your phone card now!


the use of ultra-pole of this, 64GB Surface Pro 3 and other users can rest assured that the upgrade Win10, Preparing a big USB flash drive is your first choice.