I have a iMac 20" 2.4ghz 2gig ram For a few weeks now been having problems with it running slow hanging and programs doing alsort of things like losing history in programs. But the other day it hang and had to turn it of by holding the button when tried to turn it on again it would only load till the grey screen and it had a flashing folder with a ?. tried for ages to get it to bootup but nothing so left it for a day turned it on and it booted up ok but still with the other problems. Now it hangs all the time and it wont always bootup. Anyhelp to sort this would be great as i use it for work.