|Good suggestions but not in the right order. You won't be able to defrag if the drive is full.|
Start by uninstalling programs you don't use.
Review/delete files in your user directory
Run disk cleanup off the accessories/system tools menu.
Run chkdsk /f on each partition to make sure of no file/disk corruption
Backup your data
Instead of the shrink d: and then expand c: I would suggest just deleting d: and expand c: into that space creating one large c:
This assumes d: is not a recovery partition. If it is I would not delete it and would chose a different path of cloning to a larger drive.
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