hard drive size problem

[eazy27]

I have a 30 gb and a 80 gb hd on my system running under win 2k. I started to run out of space , even though my computer told me I had 10 gb free space left, I was unable to save files to the drive. I assumed that It was probabley being used for cahcing by windows, so I threw in another 80 gb drive, and move 5 gb of files from the 30 gb drive and 15 gb of files from the 80- gb. Now My 30 gb drive shows 4.9 db free space, but I only have room for 800mb files. athe original 80 gb drvie shows 19 gb free space, but I only have 2.5 gb available to save files, and the new 80 gb drive has 57 gb free, but I only have 900 mb availabe to save files. I had norton on the system and removed that . I reset the sfcQuote back to 50 mb and purged the cache. I have defragged drives, rand norton and ontrack utilties for hd and memory , and I can't find my missing hard drive space. the first 2 drives are fat32, and I set up the last drive as a dynamic ntfs.

HELP!!!