Okay, basically I'm in trouble... My girlfriend has a MacBook from about 2007, running OS 10.5, and asked me to see if I could speed it up a bit. I'm somewhat familiar with Macs but have more knowledge on a PC. So I Googled "how to speed up a Mac" and found a site listing a few steps that may help. One of them was to install a sort of file cleanup app, like CleanApp or TidyUp. I ended up installing Yasu, since it got good reviews on Cnet, so I figured it was a solid starting point. Another one of the steps was to go to Library > Preferences > Show info, then check the box for "Locked". So I did. I wasn't able to clean anything using Yasu because I needed her password, so I closed her computer and kind of forgot about it. This morning she opened her computer after I'd left for work and saw Yasu asking for her password, so she entered it, not realizing what it was. She told me it then ran its cleaning process. When she tried to use Safari, she couldn't get to websites, getting an "unable to establish a secure connection" message. She couldn't use QuickTime, so she uninstalled it then tried to reinstall, which she apparently couldn't do. So she called me told me about her problems. The first thing I thought of was to unlock the preferences. She navigated to the folder and told me that many of her folders had duplicated themselves (ie there was "preferences" and "preferences - original") and also informed me that the box to uncheck "lock" was now greyed out. So it's locked, and staying that way... What did I do, and more importantly, how can this be fixed? Any help would be appreciated, but being that I'm over an hour away from her and I'd need to explain/instruct her over the phone, the simpler, the better. Although I understand if there is no easy fix. Thanks in advance.