Hi. I have a desk top Imac 10.6.8. I am having a lot of trouble with Youtube, safari etc. I had a browser named Opera and deleted it as it was slow. Real problems started however when I downloaded a 'clean your mac' program which I cant remember which one now. I cleaned my mac. After this in Opera all videos and clips were just a grey screen until I clicked onto them. I thought it may be Opera so thats why I deleted the browser. Now safari won't let me download Firefox , Chrome, etc. I get this message that my mac doesn't support it which is rubbish as I have had Firefox before. Any advice would be appreciated thanks. I am pretty much computer dummy. Cheers