I need to upgrade or install clean copy in the same board using ESXi 4.0
did any one have way to upgrade as i think we have new HW challenge as the CD structure changed.
and no OEM file any more

I've moved your post to the ESXi 4.0 Install Problems and Questions forum.

If you're not using an oem.tgz file with your ESXi 3.5 install then I would just upgrade - http://www.vm-help.com/esx40i/ESXi40_up ... center.php.

With a modified oem.tgz, you might still upgrade, but you have to keep in mind that ESXi 4.0 might have better files than you've included in oem.tgz. For example, the e1000e and e1000 drivers are updated, and simple.map has been expanded. So if that impacts you, then I would consider a fresh install (note that a new install with 4.0 does wipe all data on the install drive).

Or you could upgrade and then review what's in oem.tgz to see if you can go back to the default file for it.

Oem.tgz is still used with ESXi 4.0, but not for the install process. Once you have it installed and check out /bootbank/ you will find it there again.

I'm using oem.tgz when i install ESXi 3.5
how could i inject the old oem file to ESXi 4 upgrade file and wher i can fined the new drivers for ESXi 4

Which oem.tgz file did you use (or specifically did you add a driver and if so which one)?

i'm no Linux expert i have gust download the file from http://www.icjacobsen.com/dld/oem.tgz and inject it to the CD

You can inject the oem.tgz in the update .zip-package, see http://www.vm-help.com/forum/viewtopic.php?f=13&t=253, second post
for instructions

What are you using for hardware - MB / NIC / storage controller?