I bought my Studio XPS 8100 in March of 2010. It runs a clean install of Windows 10 very well. I wonder: are there other Dell PCs of that vintage or older that successfully run Windows 10?
Over the years I upgraded the hardware by adding a new power supply, graphics card and additional RAM. I also added an SSD as the boot drive and made the original HDD my data drive. I added a USB 3.0 card to accommodate USB 3.0 devices. Everything else is stock.
Windows 10 is the fourth OS to run on this computer. I replaced the original Windows 7 with a clean install of Windows 8, followed by clean installs of Windows 8.1 and now Windows 10. Dell doesn't support any of these operating systems on the Studio XPS 8100, but that clearly makes no difference.