Depending on the operating system, you can find your Cloud2Drive cache files in different locations.
If you’re running Windows XP or 2003 they are in:
C:\Documents and Settings\All Users\Application Data\Extenua\C2DCache\
If you’re running Windows Vista, 2008, 7, 2012, or 8 they are in:
C:\ProgramData\Extenua\C2DCache\