I have an Alienware 18 laptop, with a "Broadcom Corporation BCM4352 802.11ac Wireless Network Adapter [14e4:43b1] (rev 03)" WiFi card. I'm dual booting Windows 7 (home 64-bit) and Ubuntu 14.04.3 LTS. Windows is on a SSD, Ubuntu runs off of a HDD. After I installed Ubuntu (I was originally using Windows by itself) the WiFi was not working on Ubuntu.
I followed the steps described here by Chili555 How can I install Broadcom Wireless Adapter BCM4352 802.11ac PCID [14e4:43b1] (rev 03) on fresh install of Ubuntu 14.10 (Utopic Unicorn)? to install the Ubuntu driver. That fixed the problem, but now the Windows 7 WiFi does not work. It turns on, but does not detect any networks. Ethernet connections work fine. Ubuntu WiFi and Ethernet connections work fine.
I have run the Windows network diagnostic tool, tried uninstalling, reinstalling, updating, rolling back, and every combination of things for the Windows Broadcom driver, but nothing fixes the problem. Throughout all of this, the Ubuntu WiFi continues to function normally.
What did I do wrong and how can I fix it? I'm new to Linux, so I apologize if this is a dumb question, but hours of my best google searching have failed to produce results.
Update: I think I have it figured out. When I hit restart from Ubuntu, and then boot Windows, the WiFi does not work. If I shut down, and then start the computer fresh, it works. Why does this happen though? What is the difference between hitting "restart" and doing a "complete" shut down? And why did this only start happening after I installed the Ubuntu wifi driver?