i recently put an Samsung SV0844D 8.4GB(8455MB) into my new system which is having Mercury motherboard(KOB 816e TFSX ver:1.0 07/17/2001)with Award Modular BIOS v 6.00PG.In the BIOS i put both the hard disk detect mode and access on Auto mode.It detected the hard disk capacity correctly as 8.4GB(8455MB) with Cyl-16383,Hd-16,Sec-63 as was specified on the hard disk label.Even while booting just after the hard disk & CD-drive are detected a table that comes up showing the devices in the system also shows the correct capacity(8455MB).Even though the BIOS has correctly identified the hard disk i am unable to access the full 8455MB of the hard disk.
For partitioning the hard disk i used FDISK of windows 98 SE from a startup floppy disk.even though i enabled Large Disk support it shows the capacity as only 8056MB instead of 8455MB that is 400MB less.I thought that there could be a problem with FDISK and so used a windows XP bootable CD to format the whole hard disk as FAT32 but even here also the capacity was shown as only 8056MB.when this didn't work i used a Seagate's Disk Manager ver 9.45 to access the hard disk & format it.Now it showed the capacity as 8447MB but the it showed hard disk specifications as Cylinders-1027,Heads-255,Sectors-63 instead of Cylinders-16383,Heads-16,Sectors-63 as was specified on the hard disk label.i formatted the hard disk as a large partition .but after formatting & rebooting the system i was still shown the capacity as only 8056MB.I tried changing the access mode in BIOS to CHS,LBA,Large mode but it was of no help.I don't understand what exactly is the problem.please help me troubleshoot the problem and access the whole 8455MB capacity.i will be very grateful to you.

This is probably a result of how harddisk manufacturers calculate disk space, compared to operating systems and software. Manufacturers commonly calculate a megabyte as 1000 kilobytes, whereas an operating system will use 1024 kilobytes per megabyte.

The "6.4 gb" drive I am currently using is really just under 6.1 gb.

Check your drive properties under windows
For example.
My 61 gig is listed as 57.2 Gig
But as 61,477,126,144 bytes

Like sleddog said. It’s all in how you calculate the capacity
If your going to use a disk utility
Use the one from the drive manufacture For the specific drive you have

i understand that the capacity of the hard disk shown thro windows will be reduced but what i don't understand is that when using FDISK from a bootup floppy it should show the full capacity as 8455MB(8.4GB)but it is showing only around 8056MB that is 400MB less.i actually have another 40GB hard drive for which the FDISK shows its full capacity.do you think i should check this 8.4gb drive at service center

Was this drive previously used? maybe from a Compaq?

If so, and it was from a Compaq it could have a hidden "system save" partion, if not from a Compaq the existence of a hidden, non-DOS partition is still a possibility. You should use the command line option of fdisk /status to show the existing partition structure, if any. You can also use a third party partitioning program, like Partition Magic (pay) or Ranish Partition Magic (http://www.ranish.com/part/) to check the existing structure, and if need be to remove any that do exist.