[URL] Intel G33 Express [URL] INTEL Chipset 9.1.1.1015 [URL]     legacy Vista or 7 WDDM drivers work. The standard Radeon HD3450 video card is legacy so catalyst 13.1 is the max you can go. Installing a geforce GT1030 low profile card will fix the video issues. Works in the slim model or the tower. The cpu in general is very slow. Not supported does NOT mean not working. The most pressing issue is that Maximum memory: 4GB. onboard Video Steals 512 megs from system ram which makes everything slow. Realtek ALC888 HD Audio driver [URL] [URL]  
YES!  You CAN teach your OLD DELL INSPIRON 531 desktop a NEW WINDOWS 10 operating system!    First - The Bad News: Memory - boost the 531 up to its 4 Gig capacity.  The stock 2 Gigs won't cut the mustard for this. Audio - the integrated sound chip on the motherboard will sound choppy if you use the Realtek drivers and/or may not work at all giving you the dreaded NO AUDIO DEVICE FOUND.  Since the 531s are used mainly for the usual email and online surfing activities anymore (a gaming machine they're not even when they were new) ... just get a new sound card for a few bucks online and disable the integrated sound chip on the motherboard in BIOS. Upgrading to Windows 10 from XP, VISTA, SEVEN ... you need to do a clean installation or you will encounter issues like corrupt registries, applications like Adobe not working, and Microsoft Office errors after the update (where Office throws up the dialog it can't find Word, Excel, Outlook etc. even when you click on the application's executable file).  This means back up your personal files to an external hard drive. Now - The Good News: Despite the fact that the Windows 10 Upgrade notification icon tells you that the Inspiron 531's integrated NVIDIA GeForce 6150SE nForce 430 doesn't have drivers for Windows 10 and therefore won't let you upgrade to Windows 10 Home or Pro ... pay no attention to that.  You do not need to go buy a video card for this system for Windows 10. The integrated NVIDIA video chip compatible.  Download either the 32 or 64 bit Windows 8.1 GeForce Driver from NVIDIA: www.geforce.com/drivers/results/56378 Now ... how to upgrade. Once you have installed the new sound card in the 531 with your Old OS still in place and have downloaded the correct NVIDIA driver and put it on a thumbdrive ... go to microsoft's website and download the Media Creation Tool for either the 32 Bit or 64 Bit version of Windows 10: www.microsoft.com/en-us/software-download/windows10 Create either your DVD or USB bootable Windows 10 installation media using the Media Creation Tool - it will allow you to create either an installation for WINDOWS 10 HOME or WINDOWS 10 PRO.    Microsoft has officially done away with Product Keys for this mass Windows 10 upgrade until the free upgrade period ends in 2016. EVERYONE upgrading right now gets a GENERIC MICROSOFT PRODUCT KEY.  For Windows 10 HOME the upgrade key is YTMG3-N6DKC-DKB77-7M9GH-8HVX7 and the Windows 10 PRO upgrade key is VK7JG-NPHTM-C97JM-9MPGT-3V66T,  There's nothing secret about these upgrade keys and Microsoft Tech Support tells everyone these keys who have to manually upgrade after the notification wizard upgrade fails.  After the mass free upgrade ends in 2016, you'll no longer be able to activate Windows 10 with these upgrade keys.  It's up to you, but you can upgrade to either version of Windows 10 on the 531 this way right now.  I had Windows 7 Ultimate running licensed on my 531, so I installed Windows 10 Pro. While still connected to the Internet ... All you have to do at this point is insert your DVD or USB into your 531, reboot, hold down the F12 button as the 531 restarts and select either your DVD Drive or USB thumb drive to boot boot from.  Windows 10 installation begins.  Be sure to select that you want to install a new copy of Windows 10 and NOT upgrade.  Upgrading will only cause you headaches.  When prompted, put in the HOME or PRO key specific for the Windows 10 version installation DVD or USB  (can't use a PRO Key on HOME installation DVD/USB or vice versa - the Windows 10 installer will tell you you're using a key not for the installation you're doing).  When Windows 10 asks you where you want to install, delete all the existing partitions on the 531 hard drive setup shows you and tell Windows 10 to use the now un-formatted free space.  Then Windows 10 will go through asking for wifi connection information, downloading updates, asking you privacy questions (don't let Windows 10 send any diagnostic info to Microsoft), setting up a Microsoft Account and installing Windows 10. After Windows 10 is done and you're looking at the Windows 10 desktop ... get the thumb drive you copied the NVIDIA GeForce 6150SE nForce 430 Windows 8.1 drivers to and install the new video drivers.  Also install your new sound card's drivers too if Windows 10 did not already detect the sound card. And you're done.  The rest of the 531's hardware is already known by Windows 10.  It won't be the fastest computer on the block, but it's not ready for the recycling bin yet either.  Good for another couple years of surfing, email, Word, etc.   BTW - I'm using my Windows 10 Pro Inspiron 531 Desktop right now.  Good luck.   
DELL Inspiron 531 Desktop works with Windows 10 HOME or PRO - How to do it.