Just had the freakiest thing happen - my desktop folder with all my documents just disappeared right off the desktop - there one second, gone the next. I could find it in Spotlight and Recent Folders so I knew it was there, but I couldn't figure out how to get it back on the desktop. I Googled and I have to say it's happened to others and the responses to them on various help boards are so shockingly inept with not one person actually offering the simple solution that works. I called Apple and got some woman on the phone with laryngitis and not much knowledge so rather than waste my time I immediately asked for a senior tech. Once she was on the phone, she had me go to Finder, we found the folder and it was just a simple thing to drag it onto the desktop, so that was easy and hopefully it won't happen again. She then asked me to look at various things, and we found a PC listed in my list of things on this computer - she said she saw that just yesterday on someone else's computer, so we got rid of it, installed a malware search thing, searched and nothing untoward was on the computer, so she thinks it was just some weird glitch - but it's good we got rid of whatever that PC thing was and we also nuked a few programs in applications that I wasn't familiar with - stuff I may have downloaded at some point but never used.