See my answer to a similar question here. Personally I don't like the idea of moving the data to another drive in the process; this will essentially just do the same thing anyway, especially when using an SSD and could certainly cause problems if you have applications installed on the D: partition. I prefer to just move it in place (backed up, of course) and let the partitioning software take care of it. But each has their own preference and there is nothing wrong with moving it off as such.
I would recommend downloading the Ubuntu Live DVD or GParted Live CD and using GParted (included on both versions) to resize the partitions as required.
You will need to resize the D: partition, then move it to the end of the disk and then resize the C: partition. Depending on the partition structure, the D: partition may be a logical partition in an extended partition in which case you will need to resize the extended partition after moving the D: partition before you can resize the C: partition.
You can find instructions for this here among many other places.
Как устроены перегородки? Если том C: в основном разделе, а том D: в расширенном разделе? Если это так, то вам нужно уменьшить D от того места, где находится основной раздел, затем уменьшить размер расширенного раздела и только потом расширять основной.