On my production machine, my Apple MacBook Pro, I did an in place upgrade from Windows 8.1 to Windows 10. I ran into a couple of bumps and got them figured out so I thought I’d post this for others seeing the same problems. That way when combined with the power of Greyskull (AKA internet search engines) they can get answers if they hit the same issues.

The first issue I ran into had nothing to do with the MacBook Pro. I’d been short on disk space so pushed my 7 GB C:WindowsInstaller$PatchCache$ directory to another drive with a directory link. That worked fine in Windows 8.1, but about 40% through the pre boot processing in Windows 10 setup I’d get the awesome “Something Happened” error. I’d made a strong mental note that I’d moved the $PatchCatch$ directory so that was the first thing I fixed. I had to make some room on the drive so did things like deleting my Outlook .OST file, which would get recreated the next time I started Outlook.

With 9 GB free on my C: drive, and $PatchCache$ in the proper location, I tried again. The upgrade was smooth sailing at that point. Once I logged into Windows 10, and deleted Windows.Old through the Disk Cleanup Utility, I was thrilled to see my 8 GB fee space had jumped to 19.2 GB. That’s awesome when an OS upgrade gives you more space on your SSD!

As with any operating system in place upgrade, I double checked all devices in Device Manager. Everything was fine except the Bluetooth hub didn’t have a driver. No problem, I probably needed to repair the Boot Camp drivers so downloaded the latest I could find. At the time I wrote this, that’s 5.1.5621. Before I did the install, I was tired of hunching over the laptop so rebooted with my Thunderbolt monitor plugged in for the big screen glory. That was a mistake.

Running SETUP.EXE from Boot Camp gave me the option to repair and I let it do its thing. I let the system reboot, the spinning circle of dots came up indicating Windows was loading, and the machine immediately shut down. I went through the OSX to Windows startup disk dance several times but each time Windows started it always stopped. When I disconnected the Thunderbolt monitor and booted into just the laptop, the screen had that weird LSD trip look. Three or four reboots later, I had a normal screen on the laptop. Plugging the Thunderbolt monitor, rebooting, and still the same shutdown.

After these ten minutes of panic I thought to check the Device Manager. For some reason, the Generic PnP monitor was disabled. Enabling it allowed Windows to work with the Thunderbolt monitor (after the requisite reboot of course). The moral here folks is to never install Boot Camp drivers when a Thunderbolt device is on the machine. At least that’s what I learned about my 2011 MacBook Pro. Some newer machines may not have this issue.

Even though I ran the Boot Camp driver repair, when I first used the laptop on battery only, I lost the brightness controls completely across Windows 10. Again, the Generic PnP monitor was disabled so once I enabled it again when on battery everything was good.

Based on past Apple performance, we should see the official Windows 10 Boot Camp drivers in somewhere around six months. We can hope for sooner, but other than a few little twists, Apple still makes one of the best Windows 10 machines around!