Not booting after freebsd install

[Mubeesh ali]

Hi, i have an acer 5745 which had ubuntu running not booting after an
attempted freebsd install .i understand that i  might have wiped by
choosing auto partition :-( and had not written mbr so that we could
manage all from grub .now the laptop is stuck at bios splash screen.it
refuses to go even to bios setup.
please advice how i can recover and start over

Thanks
mubeesh

-- 
Best  Regards,

Mubeesh Ali.V.M