|There is no information to work with here. I'll take a guess and assume it's a brand name pc like Acer, HP, Dell etc. and the D drive is a recovery partition with limited free space on it that should not be used for storing data on.|
If that's incorrect please supply more details regarding size of your partitions and what D drive contains.
As to how to rectify a problem with a drive that's too full, is to copy files to an external drive or cd/dvd's and delete them of the full drive.