RE: Broadcom Driver Help
The Windows 7 Upgrade Advisor lists problems with the Broadcom driver but Windows 7 has the necessary driver inbuilt into the operating system.
As mentioned the cost of a full retail Windows 7/10 license is not worth the current price of the system hardware. I would instead advise taking the unofficial 10130 Insider Preview upgrade path to Windows 10 TH2 Pro:
Tech Enthusiast and Author of the Unofficial Dell Windows Reinstallation Guide