Windows 8 installation problem

Dear All,
I am having windows 8.1 in laptop hp 4520s probook (Canada spec of laptop: 500GB HDD, 4GB RAM,64 bit system). I want to install windows 8.0 due to very slow response in windows 8.1. I am not able to see my laptop screen due to very slow response of laptop. I tried to format the disk via windows 8.0 DVD. but problem is i could not installed windows 8.0. i got message that "Windows 8 cannot be installed to this disk. The selected disk has an MBR partition table. On EFI systems, Windows can only be installed to GP disks." I did not take any back up data on local drive. I am not in position to take back up data due to very slow response of my laptop.

Plesae advise me step by step so i can install windows 8.0 without formatting local drive or loosing any data stored on local drive.

Moreover, HP manufacturer (HP 4520s Probook) does not provide any mother board /audio/graphic card drivers for windows 8.0. They are providing for windows 7.0

Is it advisable to install windows 8.0 in that case ?

Regards,
maulikrb