A member of this forum gave my this instructions which has always worked for me, like T6
I haven't tried Win 8 and I hope won't have to do it in a long time, in fact I hope to skip Win 8
Open a terminal and type in
su - root password - grub
You get a grub prompt and then enter the following
take note of the report you get.
Hopefully you will be able to determine from that which of the returned locations is the PCLOS one.
Then type the following
root (hdx,y) # where the (hdx,y) is the PCLOS partition reported from the last command
setup (hdx) # again where (hdx) is the boot drive
You should get back a report which ends with "Success"
Quit the Console.
Reboot and extract the live CD and hopefully you will boot into PCLOS..