My computer has taken on a mind of its own. It started by changing my wallpaper back to a previous one then everything started going wrong. I get messages saying things are ot installed correctly when they worked fine before. When I switch on sometimes there is sound but no internet connection or vice versa. My digital camera which is straight forward plug and play is no longer accepted (when trying to import my photos nothing happens) I cannot use system retore (I get the message "system error")
sounds like you might be infected with spyware or a trojan, i would run spybot s&d and maybe trend micro housecall, http://housecall65.trendmicro.com/.