Running VirtualBox

I'm trying to run VirtualBox in Ubuntu. I just created a machine but when I run it I get this error message:

Failed to open a session for the virtual machine Windows7_inLinux_2021_01_30.

VT-x is disabled in the BIOS. (VERR_VMX_MSR_VMXON_DISABLED).

Result Code: NS_ERROR_FAILURE (0x80004005)
Component: Console
Interface: IConsole {8ab7c520-2442-4b66-8d74-4ff1e195d2b6}

Help?

Thanks. Leon