Is it possible to install BeOS to a 500Mb harddrive and then put this harddrive into a P90 with 48Mb of ram as the sole operating system and get the computer to work as i seem to be unable to do this

Which are you planning to install? Personal Edition or Pro? The Personal Edition (free) can easily be installed onto a hard drive that has been initialized (formatted) in BFS (Be File System). Once you have Personal Edition installed on a Windows or Linux machine, use Installer to install the OS onto the stand alond hard drive. As long as all the hardware is compatable in the P90 system you are moving the drive into, there should be no problems. I have found BeOS has no problem being moved from one machine to another as it does not have the problems Windows has when changing all the hardware; if the hardware is compatable, it just works. I never asks for drivers, it never asks for the installation CD. If you want, you can install it onto a drive of any size and not just limited to the 500 meg. I really don't see the point of limiting your installation to 500 meg as that runs out rather quickly once you start downloading music, movies and installing software. But if you allready have a 500 meg drive, go for it; although you may want to add another drive for storage space.

Good luck!
Cliff

What Cliff said but also.
You can put the spare HD in another CPU that has beos or a BeCD and use the Application "Installer" to put BeOS on your 500M HD. Then put the HD back in the old CPU.
Boot from floppy and when mounted use type bootman from terminal to install bootloader menu (or makebootable)