Execute o VirtualBox, clique em Settings
, selecione Sistema no painel esquerdo e, em seguida, vá na guia Processor
.
Marque a opção Ativar PAE / NX .
O que é o PAE?
The Enable PAE/NX setting determines whether the PAE and NX capabilities of the host CPU will be exposed to the virtual machine. PAE stands for Physical Address Extension. Normally, if enabled and supported by the operating system, then even a 32-bit x86 CPU can access more than 4 GB of RAM.
This is made possible by adding another 4 bits to memory addresses, so that with 36 bits, up to 64 GB can be addressed. Some operating systems (such as Ubuntu Server) require PAE support from the CPU and cannot be run in a virtual machine without it. Manual