Why Disc defragmenter locks at 53% defrag. & stating end of disc drive?

[beanodino1]

 PC system/ 98' dell dimension L400c  desktop/  intel quantum  fireball 4oomhz  processor/4GB hard driveC/ win 98'se  :  Disc defragmenter locks at 53% & the processor continues to run on with no other changes of operation?  The disc  defrag. "show details" shows that at" locked" 53% run status that the D.F. program is at the end of the  hard drive: C!!??  Also, having alot of program error's popping up & stating closing program now posts! 

[patio]

DLoad the drive manuf. diagnostics from their site...
Use the file to create a bootable CD...
Boot to the CD and run the long test.
Your drive is probably failing and this will confirm it.