Sony SVF153B1YW Operating system not found during os downgrading.


Mar 3, 2014
Hello guys,

I have a Sony SVF153B1YW which is about 2 years old. Recently, I decided to downgrade my OS from 8.1 to 7 since the ram on this system was 2 GB and 8.1 was taking up too much memory.

So I created a boot-able DVD comprising of Windows 7 installation.

I inserted the disk into the laptop and then restarted it... only to find it normally booting up windows 8.1.

I searched various other forums and found out that UEFI boot was enabled, leading to the DVD containing windows 7 installation made by me, not being read.

So, I changed the boot settings to legacy, saved it and when I restarted it, I get an error "operating system not found".

So please help and thanks in advance.

P.s- Also I tried the option Boot from USB/DVD in Vaio assist and still it shows the error "Operating System not found"

And also, I know that changing the boot mode back to UEFI fixes the problem of normal boot up... but then, I want to install windows 7.