windows 8.1 start menu screen unstable, restarts sometimes

i use toshiba satellite C855D-S5232 laptop OEM windows 7 . 18 months old
i have installed windows 8 windows 8.1 and gentoo linux in extended partitions.
i have not installed grub to mbr
before i installed windows 8.1 5 days back the system was working fine.
i have added the linux boot in widows 8 boot menu using easybcd.
i kept windows 7 as default system to boot up and there was a textual menu appearing without any problem and could boot to windows 7 windows 8 and gentoo linux
then i decided to install windows 8.1. instead of upgrading windows 8 i made a new extended partition and installed windows 8.1 separately [clean install]
works fine and i am able to boot to all 4 systems.
windows 8.1 start screen comes up sometimes or windows 7 textual menu comes up some times.
i want to use the textual menu as the graphical windows 8.1 menu wants to restart every time to boot to any other system than widows 8.1
problems started 3 rd day on.
automatic repair screen appeared 3 times but just pressing restart worked ok.
today morning the startup itself was trying to come up of windows 8.1 and restared 2 times before it appeared

i have tried rewriting seven mbr with easybcd and saved menu.
once started restarts come up with textual menu without fail every time
problem comes up only on cold boot in the morning after overnight power off.

i have not been able to find any settings problem any where

need help to solve unstable startup
any help welcome

i hope i a in the right forum for this request. if not mods kindly move it to right place

thanks in advance.
i will provide any more info if needed