64 bit Virtualisation Acer 1410

I have an Acer Aspire 1410 which has an AMD 64 bit processor. I run Linux Mint as the OS.

I use Virtualbox to run Windows XP and other Linux 32 bit clients. It rejects the use of any 64 bit OS.

All the advice I have found suggests there should be switch in the BIOS to enable 64 bit virtualisation. The BIOS screen provides ony a few basic settings. I have seen mention of "advanced" BIOS settings where 64 bit virtualisation can be enabled, but I've found no way to access these - assuming they exist at all for the AS1410.