I purchased the XPS 8900 direct from Dell. Didn't know Win7 was available, then discovered only about 1/4 of my programs installed on my Win7 system will run on Win10. So I want to uninstall Win10 and reinstall Win7. I purchased from Dell the "Win7 OS Recovery and Restore USB Key", changed the Boot Sequence, but as of yet, have been unsuccessful in re-installing Win7. I've even tried my Win7 Discs from my old computer, but I eventually receive a message stating " Windows Setup could not configure Windows to run on this computers hardware." Suggestions/Solution would be greatly appreciated. I read a previous post on this issue from "Freqmaker" that Jesse L replied to I believe privately. The post did not contain a specific solution. Thanks in advance!