Method 1: Repartitioning
1) Repartition the entire hard disk, all of them.
2) First, all the important files, with a removable hard disk copy out, and then you can re-partition the hard disk.
Method 2: Gradually move
1) If you don't want to repartition all of your hard disk, you have to take a more troublesome method to gradually move the capacity of E disk to C disk.
2) Because the partitioning and merging of disk capacity can only be done with two adjacent partitions, i.e., the E disk moves the excess to the D disk, and the D disk moves the excess to the C disk, i.e., E->D->C, so as to indirectly move the capacity of the E disk to the C disk.
Tips: Partitioning is dangerous, especially the second, a little careless, you will lose the disk in the file, it is best to split the merger partition before the copy of important documents, if you are not familiar with partitioning, do not mess around, it is best to let the professionals to help you do.