Installing Debian on a Microtel w/o OS

[Ed Heaney <epjh@speakeasy.net>]

   I'm new to Linux, and I'm trying to install Debian on a Microtel 
SYSMAR754 computer; that I bought without an operating system. I am 
using a Debian GNU/Linux 3.0 r0 "Woody" system disk.
My system has a 40G hard drive with 255 Heads; 63 Sectors per track: and 
4865 Cylinders.
I chose to have a swap partition.
The error I get when trying to write a partitions table is:
No primary partitions are marked bootable. DOS MBR cannot boot this.

Help. please.
Edward Heaney