Partition Not Recognized

I am working on reinstalling WindowsNT. Earlier I used fdisk to repartition my 6Gb hard drive into two partitions; c:=500Mb and e:=5.5Gb. That worked fine.

I have had other problems, so I am looking to reinstall again, and now fdisk is not recongizing the extended dos partition or the logical drive e:. fdisk will display the partition, but will not let me delete or modify it. It acts as though its not there, but oddly displays it in view mode (with out a drive assignment).

Do I have a bios problem? Is there some way to start from low level scratch on this hard drive?