I had a couple ohnoseconds today at work.
I'm a contractor at DataCorp, which means I'm working offsite through my computer. So, I come in today, ready to do a full day's work. I plug in my laptop, update itunes so I can listen while I work, run my registry cleaner, and click Log In.
Me: Log In.
Computer: No. Can't make me.
Me: Log In!!
Computer: No. Don't like you.
Me: Uninstall, reinstall, log in!
Computer: Neener neener neener! No.
Me: Uninstall, reboot, clean registry, fresh install, LOG IN!
Computer: No. You smell funny.
My registry cleaner, for the first time ever, interfered somehow with the login procedure. Which, since it had never happened before, meant I hadn't backed up the changes. That meant two hours on the phone with tech support getting it fixed. Finally though, we got it sorted out. I log in and go to pick up where I left off yesterday. Except last night, all data was refreshed (wiped) in that area. Ok, no big deal, I'll just reload the data I need. Except I forgot one thing. If you click "Load All," the computer doesn't just load everything. It also wipes out everything in there previously. And once you click OK, the process is unstoppable. That's why the program purposely blanks that button out on all levels (except the one I was on). AAAA! I had to sit and watch as my computer merrily cleaned out eleven extremely important files, then calculated all my data based on now completely incorrect numbers. I swear it blew a raspberry as it finished.
I spent an hour and a half rebuilding those files. Based on one!! misclick. <Sigh> Not my finest moment.