When installing ESXi on IBM Blade HS20, after you've accepted the license agreement, you get the following message:

"Installation operation Failed!
The installation operation has encountered a fatal error:
Unable to find a supported device to write the VMWare ESX Server 3.i3.5.0 image to."

Here are some steps that can help you in order to install ESXi on this machine:

1. Disable IBM MegaRaid if it has been enable from the IDE Configuration in the system BIOS
2. Boot on ESXi installation cd-rom
3. Browse this procedure, and use the section Find the device's PCI IDs using the ESXi boot cd
4. Check if you hardware is listed in the HCL Documentation
5. Use Install ESXi 3.5 to an IDE drive to modify TargetFilter.py to continue the installation process

Note: If MegaRaid was enable, it means there are two disks. Be sure that the boot sequence is correctly set, to boot on the disk which has received ESXi installation.

all links in this document have been found using the VMWare community