I have acer aspire v5-471p, it was with win8.1 and in uefi mode.
I change uefi mode to lagacy mode and change the window 8.1 to 10. Because itwas slow.
Every thing was fine but as i connected with internet in this lagacy mode , it display crashes and show double double icons and erros and lines on display , i reinstall window , and again connect with web and have same problem , so this time i install window 8.1 again , but the problem is same !!!! 
Now i change the boot mode to Uefi from lagacy , but it say , OPERATING SYSTEM NOT FOUND ,
It show the boot menu , so i try dvd and usb bootalbe media , but stiLL it is not booting from any device and after some time give the same option that , OS not found , now HELP ME , that what to do
1) if i on lagacy mode , connect with net , it show crashed display after some time double icons bubling , and lins on display
2) if i on UEFI mode , it do not boot with any bootable media , but givinG access to boot menu and setup etc....
This image is , of first problem , when i do window in lagacy mood , its fine , but after connecting to the internet it display show like this , it is not usable in this case....
I have followed tutorials to build a UEFI bootable USB and tried 2 different 64 bit versions of windows 7. Every Ocassion I try to install it will freeze on the first windows loading screen.
