According to the official information released by Microsoft, to upgrade a computer to Win 10, at least the following basic hardware conditions need to be met: CPU supports SSE2 and NX; Physical memory >; = 1GB； The system disk is in NTFS format; System disk remaining space >; 20GB. So many of our users will find that their computer hard disk space is insufficient when upgrading win 10 system, which can't meet the upgrade conditions. What should we do at this time to successfully complete the upgrade? When users try to upgrade Windows 10, the system will need to get some hard disk space from C drive to store some temporary files and backup files, but for those small-capacity devices, the storage space is already stretched. How can there be extra space to upgrade the program? Don't worry, you will find that Microsoft has made improvements in system upgrade. WindowsUpdate will pop up a window to remind you whether you need to clean the disk or use an external disk drive. This improvement of Microsoft makes the upgrade easier. You no longer need to find out which hidden useless files occupy disk space. Now, plug in a USB flash drive or a mobile hard disk with the size of 16GB, and all the problems will be solved. This window pop-up window only appears when downloading or installing a new system, so it won't interfere with other operations you are doing. In short, this function is really awesome, especially for some Windows tablets or ultrabooks with small storage space, which is undoubtedly a boon. In addition, we can manually clean up some unnecessary files in the C drive, and we can use the garbage cleaning of various computer housekeeping tools or the function of "slimming the C drive" to help clean up the space of the C drive. When using a computer at ordinary times, you should also be careful not to install tools on disk C. If the file can't be put on drive C, it shouldn't be put on drive C. Try not to have too many things on the desktop, and the recycle bin should be emptied regularly, because it also takes up the memory of drive C. Don't worry if you accidentally clean up the needed files when cleaning up the garbage of drive C. We can use the file recovery tool to help us recover the files deleted by mistake. This tool has a small memory, but it is powerful and easy to learn. You can go to official website to check the relevant tutorials, which is very practical.