And which W7?
Many of today's Dells don't support W7 and well, so many questions. The usual cause is the owner has a W10 laptop and attempted to install W7. It's complicated but I can't tell from your post where that complication is.
I am trying to install window 7 in dell core i7 system.every thing going right at he begining, but while completing installation,It gave me a message .(your window is not properly install,please reinstall the window ).I reinstall but gave me same message again.. please any one help me.