[NAME] So what OS are you running? I am sure it will run Windows 7 but I would not suggest get online.  It can still be used offline with Windows XP or Windows 7 for playing vintage games. And there is no options to go to UEFI. Even though Dell has no drivers for Windows 10. It may still run Windows 10 just fine. Windows Update may pickup most drivers and there are 3rd party driver programs also. Maybe Windows 8.1 would work if not Windows 10. Windows 8.1 is supported still. And leave Windows 11 right now. I do not understand why everyone is so hyped up about Windows 11. It has not been released yet and is only in developer release. Windows 11 is not safe to use until it's fully released. 
I have an old Studio XPS 8000 (2009 vintage).Seems to be getting slower to boot with every release of Windows so have looked at ways of speeding it up. Already have an SSD to replace the original HDD but when I was checking out about Windows 11 (not going to work with the Lynffield processor) it mentioned UEFI. I read that boot times are faster using it. Checked BIOS settings on my PC and there was no option to switch to UEFI from legacy. My Dell BIOS (A03) firmware is 2009 vintage so UEFI probably wasn't available then. All of that being said, is there any point in pursuing getting UEFI to work on my PC if it is even possible? When I use Dell support to search for drivers and firmware upgrades I get different results using my support ID vs the actual PC type which has newer BIOS firmware but I'm wary of trying it. Dell support says I cannot run Windows 10 which I've had since inception. Obviously don't care about 2009 machines (and rightly so). It asks what Windows version it is running and I have a choice of Vista or XP.
Studio XPS 8000, no UEFI, worth pursuing?