Which version of Windows are you running?  Note that this question would be better posted in the Dimension - Hard Driive fourm.  If you run fdisk to partition this drive be sure to answer yes to the question about large hard drive support.  If you are running Windows XP to partition and format your drive, XP will only allow a 32 FAT32 partition, but will allow much larger NTFS partitions.

Steve

I doubt that this is a BIOS issue because even early models of the 8100 shipped with 60 Gb drives that work with no problem.  What model hard drive is it.  Some drives have a jumper that limits the drive to 32 Gb partitions.  Check the documentation that came with your drive to see if this is enabled.  Again, you would be better off posting your question (along with all of the requested information) in the Dimension - Hard Drive forum where this problem is dealt with quite often.

Steve

try changing the jumper on the new hard drive to CS

Yes, problem solved by changing the jumper setting.

thanks

Agjamal, according to the system specifications the 8100 model will support up to 2 gigs of RDRAM.  Unfortunately you will have to use the RDRAM in your system and it isn't cheap.