How large is your hard drive and how much hard drive space do you have left?
scanned my local drives to see if I have a virus.
There are no Mac viruses.
Start up in Safe Mode.
Reset SMC. http://support.apple.com/kb/HT3964
Choose the method for:
"Resetting SMC on portables with a battery you should not remove on your own".
Reinstalling OS X is the last best option.