I recommend re-formatting the "C" drive so that there are no "leftovers" to cause problems.
If you have just one big "C" on your hard drive then you won't be very keen on this idea, but if you have your hard drive partitioned it's not too painful. I found some time ago that using a relatively small partition for "C", loading all other data and apps into other drive partitions, and just keeping the Windows stuff in "C" allows you to easily re-format and re-load if (or more like when) Windows gets screwed up.