win 7 mbr to gpt

good day all
i have a dell 990 running windows 7 pro 64bit service pack 1 from dell (installed with the dell cd)
i only use it for running my drafting software, never goes on the net.
it is installed mbr and i would like to convert it to gpt.
is there an easy way/simple to do this?

thank you torchwood
that is not exactly what i was thinking, didn't realist win7 would not run on gpt.
i'm not sure if i could install linux on the gpt along with the first partition being mbr ?

efi mode = no
bios is what i use i hate working with eif
thank you all