occupying

I have 80 GB HD, 4 Partions, WinXp+SP2 (on C) Problem is that there is a Directory Named "FOUND.000" in two Partitions (D and E) having Files with extention ".CHK" occupying abt 500 MB each. My questions are :- 1. What Type of Files/Folders is this ? 2. What does these Files/Folders mean...