Thought I my leave this half-report, half vent here. (I'll also be providing it to Microsoft). So I finally got a chance to install Windows 8 on my desktop, in my sig. Didn't pay for it; one of my professors set me up with a Dreamspark account to download it for free.
The upgrade from Win7 to Win8 seemed to go smoothly, until I tried shutting down the PC. I look away when it's shutting down, and when I look back it's showing the...log on screen? I log in and get some error message about "Apple Charger" crashing (which is odd, since I don't even have iTunes installed). I try rebooting the PC again, and it gives me Win8's new smilie BSOD and reboots, again with the error message about Apple Charger.
So yeah, I can't actually do a legitimate shut down or reboot of the PC without causing Win8 to crash. I reboot the PC again (the BSOD happens again) and go into system repair with my install disc. Meanwhile I'm looking the problem up online my laptop. I try automatic repair, doesn't detect anything. I find that "Apple Charger" is apparently some driver that causes Windows 8 to crash on shutdown and needs to be disabled using Autoruns. I'm not sure who is really to blame for this, Apple or Microsoft, but whatever, it ultimately seems like a minor nuisance to fix.
Since I'm already in system repair, I decide to try Win8's new "Refresh PC" option. I figure that it clears out temporary files and resets various settings, so even if it doesn't solve the problem, it couldn't hurt. So I use Refresh PC.
Big mistake. The first sign of trouble is that upon rebooting, Windows 8 gives me...two options to boot from? On the same drive? What? I'm confused by this, but there's no way to back out of it, so I click the top one. From there it feels almost like the first time booting up the PC upon installing Windows. Windows 8 boots, but half of my desktop icons are gone and my task bar has been cleared down to IE10 and Explorer. Something's up, I'm thinking. Have installations been broken? I start worrying that my chipset driver has been uninstalled. I check my drives, and everything is still there. I check Programs and Features, though, and...
That can't be good. I figure the registry got deleted or reset somehow. At that point I just say "Screw it", reboot the PC from the Win8 install disc, and do a clean install. It's finished now, and seems to be working alright. I still have all my files, and my documents were moved to "Windows_old"
Moral of the story?
Upgrading from Win 7 to Win 8 is not a problem-free process (it did work just fine on my laptop though, even with Ubuntu and its boot loader installed)
Refresh PC sucks hard.
As a side note, Steam, which was installed to my secondary hard drive, repaired itself like a champ after the clean install. I don't have to reinstall any of my Steam-installed games. I'm most satisfied with that.