Windows 8.1 came pre-installed with Dell Inspiron 15 3531 if you purchase it. And for Windows 7 fans, you might want to install this OS in this laptop.
This laptop has the drivers for Win 7 OS, so you can do the downgrade.
Before you do this, you should have backup your laptop, if in case you want to install Windows 8.1 OS back. This means, everything in your laptop will be gone or all wiped after Windows 7 installation process, you won’t see any of your previous files on your computer.
Since this Inspiron 15 3531 model doesn’t come with a Pro version of Windows 8.1, you will need to buy Windows 7 license key. If it is a retail disc, you will need Win 7 Service Pack 1.
You should also know that if you downgrade to Win 7, the software support of your laptop will be no longer supported by Dell, read this tut if you need your Service tag to get Dell’s support.
So it’s recommended, your laptop is fully functional before you do the downgrade/installation.
1. If you receive, “Windows cannot be installed on this disk. The selected disk is of the GPT partition style” error message on the screen where you have to select partition, you will need to create a new partition.
2. If you get this error:
“A problem has been detected and Windows has been shut dwn to prevent damage to your computer
If this is the first time you’ve seen this Stop error screen, restart your computer. If this screen apperas again, follow these step:
The BIOS in this system is not fully ACPI compliant. Please contact your System vendor for an updated BIOS.
Stop: 0x000000A5 (0x0000000000000011, 0x0000000000000008, 0xFFFFFFFFFFd16018, 0X0000000000040000)”
Try to upgrade your bios to AO2. Direct download link: http://downloads.dell.com/FOLDER02298709M/1/3531A02.exe
Video to update the BIOS of a Dell computer
To downgrade, do this at your own risk
Dell official article to downgrade to Windows 7.
1. Create a recovery media. Shut down your laptop.
2. Turn it on, press F2 to enter the BIOS
3. Then in “Boot”, choose “Boot”, choose “Boot Mode”, choose “Legacy”
Select “Disabled” on “Secure Boot Control” option.
4. Hit the F10 key, this will save all above process and exit.
5. Plugin your installation DVD or a USB drive to boot.
6. Follow the instruction to install Windows 7.
This will enable you using Windows 7 on this Dell laptop.