Can't get into KDE desktop anymore.

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http://www.linuxquestions.org – Hi, I am running KDE Linux Mint 13 on my mom's computer. She has a gateway desktop that runs great, no problems with Linux KDE. She told me it's been running slow lately so I told her about Mate desktop may be a little faster. I remotely connected to her computer and installed it using the terminal. I logged off and had her to select it and log back in. I noticed when I got connected, the icons weren't there and it was a mess. I tried different commands to fix them by looking up the correct commands like --fix-missing etc. It still wasn't working so I typed sudo -xkill all or something like (HowTos)