Gerald_Clark, thanks for your reply!
I have no file called client01.pxe... I just have my server and another machine in a VM environment. The client VM (VirtualBox) is called client01 so, if I change its name (for workstation, for exemple) it changes the name of the <file>.pxe... In the server I did nothing about it.
So, if the absolute minimum refers just to persistence, should my system boot just by using the Terminal Server app, right? Well... it is not working... I'm still getting the same error from TFTP... My VirtualBox Server and Client are in the same network.
My setup:
-SERVER VM
- (Tiny)Core 4.7.7
- Network adapter 1: (eth0) NAT
- Network adapter 2: (eth1) Internal Network
- CLIENT VM
- PXE Boot thru Network adapter 1: Internal Network