I put a 2 Gig CF in my 4000 and partitioned it. Everything seemed to go OK ,but when I started to install the OS I kept getting "not a DOS disk" error. How do you make it a DOS disk? I'm using a Sandisk card and HDtoolbox CF version.
What file system did you specify when you did the partitioning? You need an Amiga compatible file system for the boot partition, such as FFS, SFS, or PFS, as AmigaOS3.x will not boot from a FAT or NTFS partition. In other words you need to format (quick format) the partition before you can install the OS onto it.