Hi, I've had an iMac 7,1 since around 2008 (running Lion) and sadly it seems to be getting rather sick lately. For starters it is just generally really slow. I use two accounts with fast user switching on this Mac and it seems to get bogged down really easily. The internet is also really problematic. It's on a Wi-Fi connection but it frequently can't load pages in any browser and it is only fixed by turning the Wi-Fi off and then back on again. Also in one account it tells me the disk is locked when I try to use iTunes and Time Machine no longer works, the computer comes up with an error screen every few minutes saying that the Time Machine backup has failed. I have disabled resume and when I log out I untick 'Reopen windows when logging back in but every time I log in Chrome, iTunes, Pages, Preview, iCal, Word, System Preferences, SketchUp, Transmission, Awaken and Terminal all open. If I change my wallpaper the old one will be back next time I log in. Up until now the computer has been really quite reliable. Could it be some kind of problem with a particular component? Eg. hard drive failure? I have no idea what might be wrong with it. If anyone can help me out and if you have any suggestions about what do please let me know Should I wipe and reinstall Lion? Thanks, Tim.